Enantioselective hydrogenation of 4-substituted 1,2-dihydroquinolines in presence of a chiral iridium catalyst

ABSTRACT

The invention relates to a process for preparing optically active 4-substituted 1,2,3,4-tetrahydroquinolines comprising enantioselective hydrogenation of the corresponding 4-substituted 1,2-dihydroquinolines in presence of a chiral iridium (P,N)-ligand catalyst.

The invention relates to a process for preparing optically active 4-substituted 1,2,3,4-tetrahydroquinolines comprising enantioselective hydrogenation of the corresponding 4-substituted 1,2-dihydroquinolines in presence of a chiral iridium (P,N)-ligand catalyst.

It is known from EP 0 654 464 that N-acetyl-tetrahydroquinolines can be converted to the corresponding 4-aminoindane derivatives via a rearrangement reaction.

4-aminoindane derivatives are important intermediates for preparing various N-indanyl heteroaryl carboxamides having fungicidal activity (EP 0 654 464, WO 2011/162397, WO 2012/084812, WO 2015/197530).

EP 3 103 789 discloses a method for optically resolving 1,1,3-trimethyl-4-aminoindane by converting the enantiomeric mixture into the diastereomeric salts of D-tartaric acid. (R)- and (S)-1,1,3-trimethyl-4-aminoindane are obtained after separation and basification of the diastereomeric salts. This reference also discloses a method for racemizing the undesired enantiomer, so that the whole method allows for converting the undesired enantiomer into the desired enantiomer via several process steps. (R)-1,1,3-trimethyl-4-aminoindane is an important intermediate for preparing the pyrazole carboxamide fungicide inpyrfluxam.

A method for preparing chiral intermediates of N-indanyl heteroaryl carboxamides via asymmetric synthesis is also known. WO 2015/141564 describes a process for preparing optically active 4-substituted 1,2,3,4-tetrahydroquinolines, which process comprises the hydrogenation of the corresponding 4-substituted 1,2-dihydroquinolines in presence of a transition metal catalyst having an optically active ligand. The asymmetric hydrogenation of the 4-substituted NH-dihydroquinolines proceeded with moderate conversion rates (up to 62.6%) and enantioselectivity (up to 71.3% ee), whereas N-acetyl-dihydroquinolines gave even poorer conversion (up to 14%) and enantioselectivity (up to 31% ee).

In the light of the prior art described above, it is an object of the present invention to provide a process for preparing optically active 4-substituted 1,2,3,4-tetrahydroquinolines which process has advantages over the processes of the prior art. The process should allow the desired enantiomer to be prepared in high yield and high enantiomeric purity, with few process steps and few purification steps.

The object described above was achieved by a process for preparing a compound of the formula (a) or (b),

wherein

-   R¹ is selected from the group consisting of C₁-C₆-alkyl,     C₁-C₆-haloalkyl, C₁-C₆-alkoxy-C₁-C₆-alkyl, C₃-C₆-cycloalkyl,     C₆-C₁₄-aryl, or C₆-C₁₄-aryl-C₁-C₄-alkyl,     -   wherein the C₁-C₆-alkyl, C₃-C₆-cycloalkyl and the C₁-C₆-alkoxy         in the C₁-C₆-alkoxy-C₁-C₆-alkyl moiety, are optionally         substituted by 1 to 3 substituents independently selected from         the group consisting of halogen, C₁-C₄-alkoxy, C₁-C₄-haloalkyl,         C₁-C₄-haloalkoxy and phenyl, wherein the phenyl may be         substituted by one to five substituents selected independently         from each other from halogen, C₁-C₄-alkyl, C₁-C₄-alkoxy,         C₁-C₄-haloalkyl, and C₁-C₄-haloalkoxy, and     -   wherein the C₆-C₁₄-aryl and the C₆-C₁₄-aryl in the         C₆-C₁₄-aryl-C₁-C₄-alkyl moiety in each case is unsubstituted or         substituted by one to five substituents selected from the group         consisting of halogen, C₁-C₄-alkyl, C₁-C₄-haloalkyl,         C₁-C₄-alkoxy and C₁-C₄-haloalkoxy, -   R² and R³ are the same and are selected from the group consisting of     hydrogen, C₁-C₆-alkyl, C₁-C₆-haloalkyl and C₁-C₆-alkoxy-C₁-C₆-alkyl,     or -   R² and R³ together with the carbon to which they are bonded, form a     C₃-C₆-cycloalkyl ring, -   R⁴ is hydrogen, C₁-C₆-alkyl, C₁-C₆-haloalkyl, C₁-C₆-alkoxy,     C₁-C₆-haloalkoxy, C₁-C₆-alkylamino, C₂-C₆-alkenyl, C₂-C₆-alkynyl,     C₃-C₆-cycloalkyl, C₃-C₆-cycloalkyl-C₁-C₄-alkyl, C₂-C₆-alkenyloxy,     9-flurorenylmethyleneoxy, C₆-C₁₄-aryl, C₆-C₁₄-aryloxy,     C₆-C₁₄-aryl-C₁-C₄-alkyloxy or C₆-C₁₄-aryl-C₁-C₄-alkyl,     -   wherein the C₆-C₁₄-aryl as such or as part of a composite         substituent is unsubstituted or substituted by one to five         substituents selected from the group consisting of halogen,         C₁-C₄-alkyl, C₁-C₄-haloalkyl, C₁-C₄-alkoxy and C₁-C₄-haloalkoxy, -   n is 0, 1, 2, 3 or 4, -   each substituent R⁵, if present, is independently selected from the     group consisting of halogen, C₁-C₆-alkyl, C₁-C₆-haloalkyl,     C₁-C₆-alkoxy, hydroxyl, amino and —C(═O)—C₁-C₆-alkyl,

comprising enantioselective hydrogenation of a compound of the formula (II)

wherein the substituents R¹, R², R³, R⁴, R⁵ and the integer n are each as defined for the compound of the formula (Ia) or (b),

in presence of a chiral iridium catalyst,

characterized in that the chiral iridium catalyst comprises a chiral ligand of the formula (IIIa), (IIIb), (IVa) or (IVb),

wherein

-   R⁶, R⁷ and R⁸ are independently from one another selected from the     group consisting of hydrogen, halogen, C₁-C₆-alkyl, C₁-C₆-haloalkyl,     C₁-C₆-alkoxy, C₂-C₆-alkenyl, C₂-C₆-alkynyl, C₃-C₇-cycloalkyl,     C₃-C₇-cycloalkyl-C₁-C₄-alkyl, C₆-C₁₄-aryl and     C₆-C₁₄-aryl-C₁-C₄-alkyl,     -   wherein the C₁-C₆-alkyl, C₂-C₆-alkenyl, C₂-C₆-alkynyl,         C₃-C₇-cycloalkyl and the C₃-C₇-cycloalkyl in the         C₃-C₇-cycloalkyl-C₁-C₄-alkyl moiety are optionally substituted         by 1 to 3 substituents independently selected from the group         consisting of halogen, C₁-C₄-alkyl, C₁-C₄-alkoxy and         C₁-C₄-haloalkyl and C₁-C₄-haloalkoxy, and     -   wherein the C₆-C₁₄-aryl and the C₆-C₁₄-aryl in the         C₆-C₁₄-aryl-C₁-C₄-alkyl moiety are optionally substituted by one         to five substituents selected from the group consisting of         halogen, C₁-C₄-alkyl, C₁-C₄-haloalkyl, C₁-C₄-alkoxy,         C₁-C₄-haloalkoxy and phenyl, wherein the phenyl again is         unsubstituted or substituted by one to five C₁-C₆-alkyl         substituents, -   R⁹ and R¹⁰ are independently from one another selected from the     group consisting of C₁-C₆-alkyl, C₂-C₆-alkenyl, C₂-C₆-alkynyl,     C₁-C₆-alkoxy, di(C₁-C₆-alkyl)amino, C₃-C₁₂-cycloalkyl,     C₃-C₁₂-cycloalkyl-C₁-C₄-alkyl, C₆-C₁₄-aryl, C₆-C₁₄-aryloxy and     C₆-C₁₄-aryl-C₁-C₄-alkyl,     -   wherein the C₁-C₆-alkyl, C₂-C₆-alkenyl, C₂-C₆-alkynyl,         C₁-C₆-alkoxy and di(C₁-C₆-alkyl)amino, are optionally         substituted by 1 to 3 substituents independently selected from         the group consisting of halogen, C₁-C₄-alkoxy, C₁-C₄-haloalkyl,         C₁-C₄-haloalkoxy and phenyl, wherein the phenyl may be         substituted by one to five substituents selected independently         from each other from halogen, C₁-C₄-alkyl, C₁-C₄-alkoxy,         C₁-C₄-haloalkyl, and C₁-C₄-haloalkoxy, and     -   wherein the C₆-C₁₄-aryl, C₆-C₁₄-aryloxy and C₃-C₁₂-cycloalkyl,         in each case as such or as part of a composite substituent, are         optionally substituted by one to five substituents selected from         the group consisting of halogen, C₁-C₄-alkyl, C₁-C₄-haloalkyl,         C₁-C₄-alkoxy, C₁-C₄-haloalkoxy and phenyl, wherein the phenyl is         unsubstituted or substituted by one to five C₁-C₆-alkyl         substituents or -   R⁹ and R¹⁰ together with the phosphorus atom to which they are     bonded, form a phospholane ring, which may be substituted with one     or two C₁-C₆-alkyl groups, or -   R⁹ and R¹⁰ together form

-   -   where the bonds identified by “x” and “y” are both bonded         directly to the phosphorus atom,

-   p and q are independently from one another selected from 0, 1 and 2,

-   R¹¹ and R¹² are independently selected from C₁-C₆-alkyl and phenyl,     which may be substituted by one to five substituents selected from     the group consisting of halogen, C₁-C₄-alkyl, C₁-C₄-alkoxy and     phenyl, which may be substituted by one or two C₁-C₄-alkyl     substituents,

-   m is 1 or 2,

-   A is

-   -   where the bond identified by “*” is bonded directly to the         phosphorus atom and where the bond identified by “#” is bonded         directly to the oxazoline moiety,

-   R¹³ is C₁-C₆-alkyl, C₁-C₆-haloalkyl, C₃-C₁₂-cycloalkyl,     C₃-C₁₂-cycloalkyl-C₁-C₄-alkyl, C₁-C₄-alkyl-C₃-C₇-cycloalkyl,     C₆-C₁₄-aryl or C₆-C₁₄-aryl-C₁-C₄-alkyl,     -   wherein the C₆-C₁₄-aryl and the C₆-C₁₄-aryl in the         C₆-C₁₄-aryl-C₁-C₄-alkyl moiety in each case is unsubstituted or         substituted by one to five substituents selected from the group         consisting of halogen, C₁-C₄-alkyl, C₁-C₄-haloalkyl,         C₁-C₄-alkoxy and C₁-C₄-haloalkoxy,

-   R¹⁴ and R¹⁵ are independently from one another selected from the     group consisting of hydrogen, C₁-C₆-alkyl, C₁-C₆-haloalkyl,     C₃-C₁₂-cycloalkyl, C₃-C₇-cycloalkyl-C₁-C₄-alkyl,     C₁-C₄-alkyl-C₃-C₇-cycloalkyl, C₆-C₁₄-aryl and     C₆-C₁₄-aryl-C₁-C₄-alkyl,     -   wherein the C₆-C₁₄-aryl and the C₆-C₁₄-aryl in the         C₆-C₁₄-aryl-C₁-C₄-alkyl moiety in each case is unsubstituted or         substituted by one to five substituents selected from the group         consisting of halogen, C₁-C₄-alkyl, C₁-C₄-haloalkyl,         C₁-C₄-alkoxy and C₁-C₄-haloalkoxy, or

-   R¹⁴ and R¹⁵ together with the carbon to which they are bonded, form     a C₅-C₆-cycloalkyl ring,

-   R¹⁶ and R¹⁷ are independently from one another selected from the     group consisting of C₁-C₆-alkyl, C₂-C₆-alkenyl, C₂-C₆-alkynyl,     C₁-C₆-alkoxy, di(C₁-C₆-alkyl)amino, C₃-C₁₂-cycloalkyl,     C₃-C₁₂-cycloalkyl-C₁-C₄-alkyl, C₆-C₁₄-aryl, C₆-C₁₄-aryloxy and     C₆-C₁₄-aryl-C₁-C₄-alkyl,     -   wherein the C₁-C₆-alkyl, C₂-C₆-alkenyl, C₂-C₆-alkynyl,         C₁-C₆-alkoxy, C₁-C₆-cycloalkyl and di(C₁-C₆-alkyl)amino, are         optionally substituted by 1 to 3 substituents independently         selected from the group consisting of halogen, C₁-C₄-alkoxy,         C₁-C₄-haloalkyl, C₁-C₄-haloalkoxy and phenyl, wherein the phenyl         may be substituted by one to five substituents selected         independently from each other from halogen, C₁-C₄-alkyl, phenyl,         C₁-C₄-alkoxy, C₁-C₄-haloalkyl, and C₁-C₄-haloalkoxy, and     -   wherein the C₆-C₁₄-aryl, the C₆-C₁₄-aryl in the         C₆-C₁₄-aryl-C₁-C₄-alkyl, the C₆-C₁₄-aryloxy and         C₃-C₁₂-cycloalkyl, in each case as such or as part of a         composite substituent, are optionally substituted by one to five         substituents selected from the group consisting of halogen,         C₁-C₄-alkyl, phenyl, C₁-C₄-haloalkyl, C₁-C₄-alkoxy and         C₁-C₄-haloalkoxy, or

-   R¹⁶ and R¹⁷ together with the phosphorus atom to which they are     bonded, form a phospholane ring, which may be substituted with one     or two C₁-C₆-alkyl groups, or

-   R¹⁶ and R¹⁷ together form

-   -   where the bonds identified by “x” and “y” are both bonded         directly to the phosphorus atom,

-   p and q are independently from one another selected from 0, 1 and 2,     and

-   R¹¹ and R¹² are independently selected from C₁-C₆-alkyl and phenyl,     which may be substituted by one to five substituents selected from     the group consisting of halogen, C₁-C₄-alkyl, C₁-C₄-alkoxy and     phenyl, which may be substituted by one or two C₁-C₄-alkyl     substituents.

It has been found, surprisingly, that optically active 4-substituted 1,2,3,4-tetrahydroquinolines (Ia and Ib) can be prepared in high yields and excellent enantioselectivity by enantioselective hydrogenation of the corresponding 4-substituted 1,2-dihydroquinolines (II) in presence of a chiral iridium (P,N)-ligand catalyst.

Definitions

In the definitions of the symbols given in the above formulae, collective terms were used, which are generally representative of the following substituents:

Halogen: fluorine, chlorine, bromine or iodine, preferably fluorine, chlorine or bromine, and more preferably fluorine or chlorine.

Alkyl: saturated, straight-chain or branched hydrocarbyl substituents having 1 to 6, preferably 1 to 4 carbon atoms, for example (but not limited to) C₁-C₆-alkyl such as methyl, ethyl, propyl (n-propyl), 1-methylethyl (iso-propyl), butyl (n-butyl), 1-methylpropyl (sec-butyl), 2-methylpropyl (iso-butyl), 1,1-dimethylethyl (tert-butyl), pentyl, 1-methylbutyl, 2-methylbutyl, 3-methylbutyl, 2,2-dimethylpropyl, 1-ethylpropyl, 1,1-dimethylpropyl, 1,2-dimethylpropyl, hexyl, 1-methylpentyl, 2-methylpentyl, 3-methylpentyl, 4-methylpentyl, 1,1-dimethylbutyl, 1,2-dimethylbutyl, 1,3-dimethylbutyl, 2,2-dimethylbutyl, 2,3-dimethylbutyl, 3,3-dimethylbutyl, 1-ethylbutyl, 2-ethylbutyl, 1,1,2-trimethylpropyl, 1,2,2-trimethylpropyl, 1-ethyl-1-methylpropyl and 1-ethyl-2-methylpropyl. Particularly, said group is a C₁-C₄-alkyl group, e.g. a methyl, ethyl, propyl, 1-methylethyl (isopropyl), butyl, 1-methylpropyl (sec-butyl), 2-methylpropyl (iso-butyl) or 1,1-dimethylethyl (tert-butyl) group. This definition also applies to alkyl as part of a composite substituent, for example C₃-C₆-cycloalkyl-C₁-C₄-alkyl, C₆-C₁₄-aryl-C₁-C₄-alkyl etc., unless defined elsewhere.

Alkenyl: unsaturated, straight-chain or branched hydrocarbyl substituents having 2 to 6, preferably 2 to 4 carbon atoms and one double bond in any position, for example (but not limited to) C₂-C₆-alkenyl such as vinyl, allyl, (E)-2-methylvinyl, (Z)-2-methylvinyl, isopropenyl, homoallyl, (E)-but-2-enyl, (Z)-but-2-enyl, (E)-but-1-enyl, (Z)-but-1-enyl, 2-methylprop-2-enyl, 1-methylprop-2-enyl, 2-methylprop-1-enyl, (E)-1-methylprop-1-enyl, (Z)-1-methylprop-1-enyl, pent-4-enyl, (E)-pent-3-enyl, (Z)-pent-3-enyl, (E)-pent-2-enyl, (Z)-pent-2-enyl, (E)-pent-1-enyl, (Z)-pent-1-enyl, 3-methylbut-3-enyl, 2-methylbut-3-enyl, 1-methylbut-3-enyl, 3-methylbut-2-enyl, (E)-2-methylbut-2-enyl, (Z)-2-methylbut-2-enyl, (E)-1-methylbut-2-enyl, (Z)-1-methylbut-2-enyl, (E)-3-methylbut-1-enyl, (Z)-3-methylbut-1-enyl, (E)-2-methylbut-1-enyl, (Z)-2-methylbut-1-enyl, (E)-1-methylbut-1-enyl, (Z)-1-methylbut-1-enyl, 1,1-dimethylprop-2-enyl, 1-ethylprop-1-enyl, 1-propylvinyl, 1-isopropylvinyl, (E)-3,3-dimethylprop-1-enyl, (Z)-3,3-dimethylprop-1-enyl, hex-5-enyl, (E)-hex-4-enyl, (Z)-hex-4-enyl, (E)-hex-3-enyl, (Z)-hex-3-enyl, (E)-hex-2-enyl, (Z)-hex-2-enyl, (E)-hex-1-enyl, (Z)-hex-1-enyl, 4-methylpent-4-enyl, 3-methylpent-4-enyl, 2-methylpent-4-enyl, 1-methylpent-4-enyl, 4-methylpent-3-enyl, (E)-3-methylpent-3-enyl, (Z)-3-methylpent-3-enyl, (E)-2-methylpent-3-enyl, (Z)-2-methylpent-3-enyl, (E)-1-methylpent-3-enyl, (Z)-1-methylpent-3-enyl, (E)-4-methylpent-2-enyl, (Z)-4-methylpent-2-enyl, (E)-3-methylpent-2-enyl, (Z)-3-methylpent-2-enyl, (E)-2-methylpent-2-enyl, (Z)-2-methylpent-2-enyl, (E)-1-methylpent-2-enyl, (Z)-1-methylpent-2-enyl, (E)-4-methylpent-1-enyl, (Z)-4-methylpent-1-enyl, (E)-3-methylpent-1-enyl, (Z)-3-methylpent-1-enyl, (E)-2-methylpent-1-enyl, (Z)-2-methylpent-1-enyl, (E)-1-methylpent-1-enyl, (Z)-1-methylpent-1-enyl, 3-ethylbut-3-enyl, 2-ethylbut-3-enyl, 1-ethylbut-3-enyl, (E)-3-ethylbut-2-enyl, (Z)-3-ethylbut-2-enyl, (E)-2-ethylbut-2-enyl, (Z)-2-ethylbut-2-enyl, (E)-1-ethylbut-2-enyl, (Z)-1-ethylbut-2-enyl, (E)-3-ethylbut-1-enyl, (Z)-3-ethylbut-1-enyl, 2-ethylbut-1-enyl, (E)-1-ethylbut-1-enyl, (Z)-1-ethylbut-1-enyl, 2-propylprop-2-enyl, 1-propylprop-2-enyl, 2-isopropylprop-2-enyl, 1-isopropylprop-2-enyl, (E)-2-propylprop-1-enyl, (Z)-2-propylprop-1-enyl, (E)-1-propylprop-1-enyl, (Z)-1-propylprop-1-enyl, (E)-2-isopropylprop-1-enyl, (Z)-2-isopropylprop-1-enyl, (E)-1-isopropylprop-1-enyl, (Z)-1-isopropylprop-1-enyl, 1-(1,1-dimethylethyl)ethenyl, buta-1,3-dienyl, penta-1,4-dienyl, hexa-1,5-dienyl or methylhexadienyl. Particularly, said group is vinyl or allyl. This definition also applies to alkenyl as part of a composite substituent unless defined elsewhere.

Alkynyl: straight-chain or branched hydrocarbyl substituents having 2 to 8, preferably 2 to 6, and more preferably 2 to 4 carbon atoms and one triple bond in any position, for example (but not limited to) C₂-C₆-alkynyl, such as ethynyl, prop-1-ynyl, prop-2-ynyl, but-1-ynyl, but-2-ynyl, but-3-ynyl, 1-methylprop-2-ynyl, pent-1-ynyl, pent-2-ynyl, pent-3-ynyl, pent-4-ynyl, 2-methylbut-3-ynyl, 1-methylbut-3-ynyl, 1-methylbut-2-ynyl, 3-methylbut-1-ynyl, 1-ethylprop-2-ynyl, hex-1-ynyl, hex-2-ynyl, hex-3-ynyl, hex-4-ynyl, hex-5-ynyl, 3-methylpent-4-ynyl, 2-methylpent-4-ynyl, 1-methylpent-4-ynyl, 2-methylpent-3-ynyl, 1-methylpent-3-ynyl, 4-methylpent-2-ynyl, 1-methylpent-2-ynyl, 4-methylpent-1-ynyl, 3-methylpent-1-ynyl, 2-ethylbut-3-ynyl, 1-ethylbut-3-ynyl, 1-ethylbut-2-ynyl, 1-propylprop-2-ynyl, 1-isopropylprop-2-ynyl, 2,2-dimethylbut-3-ynyl, 1,1-dimethylbut-3-ynyl, 1,1-dimethylbut-2-ynyl, or 3,3-dimethylbut-1-ynyl group. Particularly, said alkynyl group is ethynyl, prop-1-ynyl, or prop-2-ynyl. This definition also applies to alkynyl as part of a composite substituent unless defined elsewhere.

Alkylamino: monoalkylamino or dialkylamino, wherein monoalkylamino represents an amino radical having one alkyl residue with 1 to 4 carbon atoms attached to the nitrogen atom. Non-limiting examples include methylamino, ethylamino, n-propylamino, isopropylamino, n-butylamino and tert-butylamino. Wherein dialkylamino represents an amino radical having two independently selected alkyl residues with 1 to 4 carbon atoms each attached to the nitrogen atom. Non-limiting examples include N,N-dimethylamino, N,N-diethylamino, N,N-diisopropylamino, N-ethyl-N-methylamino, N-methyl-N-n-propylamino, N-iso-propyl-N-n-propylamino and N-tert-butyl-N-methylamino.

Alkoxy: saturated, straight-chain or branched alkoxy substituents having 1 to 6, more preferably 1 to 4 carbon atoms, for example (but not limited to) C₁-C₆-alkoxy such as methoxy, ethoxy, propoxy, 1-methylethoxy, butoxy, 1-methylpropoxy, 2-methylpropoxy, 1,1-dimethylethoxy, pentoxy, 1-methylbutoxy, 2-methylbutoxy, 3-methylbutoxy, 2,2-dimethylpropoxy, 1-ethylpropoxy, 1,1-dimethylpropoxy, 1,2-dimethylpropoxy, hexoxy, 1-methylpentoxy, 2-methylpentoxy, 3-methylpentoxy, 4-methylpentoxy, 1,1-dimethylbutoxy, 1,2-dimethylbutoxy, 1,3-dimethylbutoxy, 2,2-dimethylbutoxy, 2,3-dimethylbutoxy, 3,3-dimethylbutoxy, 1-ethylbutoxy, 2-ethylbutoxy, 1,1,2-trimethylpropoxy, 1,2,2-trimethylpropoxy, 1-ethyl-1-methylpropoxy and 1-ethyl-2-methylpropoxy. This definition also applies to alkoxy as part of a composite substituent unless defined elsewhere.

Cycloalkyl: mono- or polycyclic, saturated hydrocarbyl substituents having 3 to 12, preferably 3 to 8 and more preferably 3 to 6 carbon ring members, for example (but not limited to) cyclopropyl, cyclopentyl, cyclohexyl and adamantyl. This definition also applies to cycloalkyl as part of a composite substituent, for example C₃-C₆-cycloalkyl-C₁-C₄-alkyl, unless defined elsewhere.

Haloalkyl: straight-chain or branched alkyl substituents having 1 to 6, preferably 1 to 4 carbon atoms (as specified above), where some or all of the hydrogen atoms in these groups are replaced by halogen atoms as specified above, for example (but not limited to) C₁-C₃-haloalkyl such as chloromethyl, bromomethyl, dichloromethyl, trichloromethyl, fluoromethyl, difluoromethyl, trifluoromethyl, chlorofluoromethyl, dichlorofluoromethyl, chlorodifluoromethyl, 1-chloroethyl, 1-bromoethyl, 1-fluoroethyl, 2-fluoroethyl, 2,2-difluoroethyl, 2,2,2-trifluoroethyl, 2-chloro-2-fluoroethyl, 2-chloro-2,2-difluoroethyl, 2,2-dichloro-2-fluoroethyl, 2,2,2-trichloroethyl, pentafluoroethyl and 1,1,1-trifluoroprop-2-yl. This definition also applies to haloalkyl as part of a composite substituent unless defined elsewhere.

Haloalkenyl and haloalkynyl are defined analogously to haloalkyl except that, instead of alkyl groups, alkenyl and alkynyl groups are present as part of the substituent.

Haloalkoxy: straight-chain or branched alkoxy substituents having 1 to 6, preferably 1 to 4 carbon atoms (as specified above), where some or all of the hydrogen atoms in these groups are replaced by halogen atoms as specified above, for example (but not limited to) C₁-C₃-haloalkoxy such as chloromethoxy, bromomethoxy, dichloromethoxy, trichloromethoxy, fluoromethoxy, difluoromethoxy, trifluoromethoxy, chlorofluoromethoxy, dichlorofluoromethoxy, chlorodifluoromethoxy, 1-chloroethoxy, 1-bromoethoxy, 1-fluoroethoxy, 2-fluoroethoxy, 2,2-difluoroethoxy, 2,2,2-trifluoroethoxy, 2-chloro-2-fluoroethoxy, 2-chloro-2,2-difluoroethoxy, 2,2-dichloro-2-fluoroethoxy, 2,2,2-trichloroethoxy, pentafluoroethoxy and 1,1,1-trifluoroprop-2-oxy. This definition also applies to haloalkoxy as part of a composite substituent, unless defined elsewhere.

Aryl: mono-, bi- or tricyclic aromatic or partially aromatic substituents having 6 to 14 carbon atoms, for example (but not limited to) phenyl, naphthyl, tetrahydronapthyl, indenyl and indanyl. The binding to the superordinate general structure can be carried out via any possible ring member of the aryl residue. Aryl is preferably selected from phenyl, 1-naphthyl, 2-naphthyl, 9-phenantryl und 9-antracenyl. Phenyl is particularly preferred.

The term “enantioselective” as used herein means that one of the two possible enantiomers of the hydrogenation product, namely the enantiomer of the formula (Ia) or the enantiomer of the formula (Ib), is preferably formed. The “enantiomeric excess” or “ee” indicates the degree of enantioselectivity:

${ee} = {\frac{{{major}\mspace{14mu} {enantiomer}\mspace{11mu} ({mol})} - {{minor}\mspace{14mu} {enantiomer}\mspace{14mu} ({mol})}}{{{major}\mspace{14mu} {enantiomer}\mspace{11mu} ({mol})} + {{minor}\mspace{14mu} {enantiomer}\mspace{14mu} ({mol})}} \times 100}$

The major enantiomer can be controlled by the selection of the chiral ligand, for example by selecting the chiral ligand of the formula (IIIa) or the opposite enantiomer (the ligand of the formula (IIIb)), or respectively by selecting the chiral ligand of the formula (IVa) or the opposite enantiomer (the ligand of the formula (IVb)).

The process according to the invention is used for preparing the compound of the formula (a) or (b), preferably (Ia).

Preferred are compounds of the formula (Ia) or (Ib), in particular (Ia), wherein the substituents are defined as follows:

-   R¹ is C₁-C₆-alkyl or C₆-C₁₄-aryl-C₁-C₄-alkyl,     -   wherein C₆-C₁₄-aryl in the C₆-C₁₄-aryl-C₁-C₄-alkyl moiety is         unsubstituted or substituted by one to five substituents         selected from the group consisting of halogen, C₁-C₄-alkyl,         C₁-C₄-haloalkyl, C₁-C₄-alkoxy and C₁-C₄-haloalkoxy -   R² and R³ are the same and are selected from C₁-C₄-alkyl, -   R⁴ is C₁-C₄-alkyl, C₁-C₄-haloalkyl, C₁-C₄-alkoxy, C₁-C₄-haloalkoxy,     phenyl or benzyl, -   n is 0, 1 or 2, -   each substituent R⁵, if present, is independently selected from the     group consisting of halogen, C₁-C₆-alkyl and C₁-C₆-haloalkyl.

More preferred are compounds of the formula (Ia) or (Ib), in particular (Ia), wherein the substituents are defined as follows:

-   R¹ is C₁-C₆-alkyl -   R² and R³ are the same and are selected from C₁-C₄-alkyl, -   R⁴ is C₁-C₄-alkyl, C₁-C₄-haloalkyl, phenyl or benzyl, -   n is 0, 1 or 2, -   each substituent R⁵, if present, is independently selected from the     group consisting of halogen and C₁-C₆-alkyl.

Even more preferred are compounds of the formula (Ia) or (Ib), in particular (Ia), wherein the substituents are defined as follows:

-   R¹ is methyl, ethyl or n-propyl, -   R² and R³ are methyl, -   R⁴ is C₁-C₄-alkyl, -   n is 0, 1 or 2, -   each substituent R⁵, if present, is independently selected from the     group consisting of halogen and C₁-C₆-alkyl.

Most preferred are compounds of the formula (Ia) or (Ib), in particular (Ia), wherein the substituents are defined as follows:

-   R¹ is methyl or n-propyl, -   R² and R³ are methyl, -   R⁴ is methyl, -   n is 0 or 1,     -   substituent R⁵, if present, is fluorine.

The process according to the invention comprises enantioselective hydrogenation of the compound of the formula (II). The substituents R¹, R², R³, R⁴, R⁵ and the integer n in the compound of the formula (II) are each as defined for the compound of the formula (Ia) or (b).

The enantioselective hydrogenation of the compound of the formula (II) is conducted in presence of a chiral iridium catalyst comprising a chiral ligand of the formula (IIIa), (IIIb), (IVa) or (IVb).

In a preferred embodiment of the process according to the invention, the substituents of formulae (Ia), (Ib), (II), (IIIa), (IIIb), (IVa), (IVb) are defined as follows:

-   R¹ is C₁-C₆-alkyl or C₆-C₁₄-aryl-C₁-C₄-alkyl,     -   wherein C₆-C₁₄-aryl in the C₆-C₁₄-aryl-C₁-C₄-alkyl moiety is         unsubstituted or substituted by one to five substituents         selected from the group consisting of halogen, C₁-C₄-alkyl,         C₁-C₄-haloalkyl, C₁-C₄-alkoxy and C₁-C₄-haloalkoxy -   R² and R³ are the same and are selected from C₁-C₄-alkyl, -   R⁴ is C₁-C₄-alkyl, C₁-C₄-haloalkyl, C₁-C₄-alkoxy, C₁-C₄-haloalkoxy,     phenyl or benzyl, -   n is 0, 1 or 2, -   each substituent R⁵, if present, is independently selected from the     group consisting of halogen, C₁-C₆-alkyl and C₁-C₆-haloalkyl, -   R⁶ is C₁-C₆-alkyl, C₁-C₆-haloalkyl, C₃-C₇-cycloalkyl or C₆-C₁₄-aryl,     -   wherein the C₆-C₁₄-aryl is unsubstituted or substituted by one         to five substituents selected from the group consisting of         halogen, C₁-C₄-alkyl, C₁-C₄-haloalkyl, C₁-C₄-alkoxy,         C₁-C₄-haloalkoxy and phenyl, wherein the phenyl again is         unsubstituted or substituted by one to five C₁-C₆-alkyl         substituents, -   R⁷ and R⁸ are independently from one another hydrogen selected from     the group consisting of hydrogen, C₁-C₆-alkyl, C₆-C₁₄-aryl,     C₁-C₆-alkoxy or C₁-C₆-haloalkyl,     -   wherein the C₆-C₁₄-aryl is unsubstituted or substituted by one         to five C₁-C₄-alkyl substituents, -   R⁹ and R¹⁰ are independently from one another selected from the     group consisting of C₁-C₆-alkyl, C₁-C₆-alkoxy, di(C₁-C₆-alkyl)amino,     C₃-C₁₂-cycloalkyl, C₆-C₁₄-aryl, C₆-C₁₄-aryloxy and     C₆-C₁₄-aryl-C₁-C₄-alkyl,     -   wherein the C₁-C₆-alkyl, C₁-C₆-alkoxy and di(C₁-C₆-alkyl)amino         moieties are optionally substituted by 1 to 3 substituents         independently selected from the group consisting of halogen,         C₁-C₄-alkoxy, C₁-C₄-haloalkyl, C₁-C₄-haloalkoxy and phenyl,         wherein the phenyl may be substituted by one to five         substituents selected independently from each other from         halogen, C₁-C₄-alkyl, C₁-C₄-alkoxy, C₁-C₄-haloalkyl, and         C₁-C₄-haloalkoxy, and     -   wherein the C₆-C₁₄-aryl, C₆-C₁₄-aryloxy and C₃-C₁₂-cycloalkyl,         as such or as part of a composite substituent, in each case is         unsubstituted or substituted by one to five substituents         selected from the group consisting of halogen, C₁-C₄-alkyl,         C₁-C₄-haloalkyl, C₁-C₄-alkoxy, C₁-C₄-haloalkoxy and phenyl,         wherein the phenyl is unsubstituted or substituted by one to         five C₁-C₆-alkyl substituents or -   R⁹ and R¹⁰ together with the phosphorus atom to which they are     bonded, form a phospholane ring, which may be substituted with one     or two C₁-C₆-alkyl groups, -   m is 1 or 2, -   A is

-   -   where the bond identified by “*” is bonded directly to the         phosphorus atom and where the bond identified by “#” is bonded         directly to the oxazoline moiety,

-   R¹³ is C₃-C₆-alkyl, C₃-C₁₂-cycloalkyl, C₆-C₁₄-aryl or     C₆-C₁₄-aryl-C₁-C₄-alkyl,     -   wherein the C₆-C₁₄-aryl and the C₆-C₁₄-aryl in the         C₆-C₁₄-aryl-C₁-C₄-alkyl moiety in each case is unsubstituted or         substituted by one to five substituents selected from the group         consisting of halogen, C₁-C₄-alkyl, C₁-C₄-haloalkyl,         C₁-C₄-alkoxy and C₁-C₄-haloalkoxy,

-   R¹⁴ and R¹⁵ are independently from one another selected from the     group consisting of C₁-C₆-alkyl, C₃-C₁₂-cycloalkyl, C₆-C₁₄-aryl and     C₆-C₁₄-aryl-C₁-C₄-alkyl,     -   wherein the C₆-C₁₄-aryl and the C₆-C₁₄-aryl in the         C₆-C₁₄-aryl-C₁-C₄-alkyl moiety is unsubstituted or substituted         by one to five substituents selected from the group consisting         of halogen, C₁-C₄-alkyl, C₁-C₄-haloalkyl, C₁-C₄-alkoxy and         C₁-C₄-haloalkoxy, or

-   R¹⁴ and R¹⁵ together with the carbon to which they are bonded, form     a C₅-C₆-cycloalkyl ring,

-   R¹⁶ and R¹⁷ are independently from one another selected from the     group consisting of C₁-C₆-alkyl, C₃-C₁₂-cycloalkyl, C₆-C₁₄-aryl and     C₆-C₁₄-aryl-C₁-C₄-alkyl,     -   wherein the C₁-C₆-alkyl is optionally substituted by 1 to 3         substituents independently selected from the group consisting of         halogen, C₁-C₄-alkoxy, C₁-C₄-haloalkyl, C₁-C₄-haloalkoxy and         phenyl, wherein the phenyl may be substituted by one to five         substituents selected independently from each other from         halogen, C₁-C₄-alkyl, phenyl, C₁-C₄-alkoxy, C₁-C₄-haloalkyl, and         C₁-C₄-haloalkoxy, and     -   wherein the C₆-C₁₄-aryl and the C₆-C₁₄-aryl in the         C₆-C₁₄-aryl-C₁-C₄-alkyl moiety in each case is unsubstituted or         substituted by one to five substituents selected from the group         consisting of halogen, C₁-C₄-alkyl, C₁-C₄-haloalkyl,         C₁-C₄-alkoxy and C₁-C₄-haloalkoxy, or

-   R¹⁶ and R¹⁷ together with the phosphorus atom to which they are     bonded, form a phospholane ring, which may be substituted with one     or two C₁-C₆-alkyl groups.

In a more preferred embodiment of the process according to the invention, the substituents of formulae (Ia), (Ib), (II), (IIIa), (IIIb), (IVa), (IVb) are defined as follows:

-   R¹ is C₁-C₆-alkyl, -   R² and R³ are the same and are selected from C₁-C₄-alkyl, -   R⁴ is C₁-C₄-alkyl, C₁-C₄-haloalkyl, C₁-C₄-alkoxy, C₁-C₄-haloalkoxy,     phenyl or benzyl, -   n is 0, 1 or 2,     -   each substituent R⁵, if present, is independently selected from         the group consisting of halogen, C₁-C₆-alkyl and         C₁-C₆-haloalkyl, -   R⁶ is selected from the group consisting of 1-naphtyl, 2-naphtyl,     9-antracenyl, 9-phenantryl or phenyl, which is unsubstituted or     substituted by one to five substituents selected from the group     consisting of halogen, C₁-C₄-alkoxy, C₁-C₄-alkyl, C₁-C₄-haloalkyl     and phenyl,     -   wherein the phenyl again is unsubstituted or substituted by one         to five C₁-C₆-alkyl substituents, -   R⁷ and R⁸ are independently from one another hydrogen or     C₁-C₆-alkyl, -   R⁹ and R¹⁰ are independently from one another selected from the     group consisting of ethyl, iso-propyl, sec-butyl, iso-butyl,     tert-butyl, cyclohexyl, cyclopentyl, adamantyl and benzyl, and -   m is 1 or 2, -   A is

-   -   where the bond identified by “*” is bonded directly to the         phosphorus atom and where the bond identified by “#” is bonded         directly to the oxazoline moiety,

-   R¹³ is selected from the group consisting of C₃-C₆-alkyl,     C₃-C₁₂-cycloalkyl, C₆-C₁₄-aryl or C₆-C₁₄-aryl-C₁-C₄-alkyl,     -   wherein the C₆-C₁₄-aryl and the C₆-C₁₄-aryl in the         C₆-C₁₄-aryl-C₁-C₄-alkyl moiety in each case is unsubstituted or         substituted by one to five substituents selected from the group         consisting of halogen or C₁-C₄-alkyl,

-   R¹⁴ and R¹⁵ are independently from one another selected from the     group consisting of C₁-C₆-alkyl and C₆-aryl-C₁-C₄-alkyl,     -   wherein the C₆-aryl in the C₆-C₁₄-aryl-C₁-C₄-alkyl moiety is         unsubstituted or substituted by one to five substituents         selected from the group consisting of halogen and C₁-C₄-alkyl,

-   R¹⁴ and R¹⁵ together with the carbon to which they are bonded, form     a C₅-C₆-cycloalkyl ring,

-   R¹⁶ and R¹⁷ are independently from one another selected from the     group consisting of C₁-C₆-alkyl, C₃-C₁₂-cycloalkyl, C₆-C₁₄-aryl and     C₆-C₁₄-aryl-C₁-C₄-alkyl,     -   wherein the C₆-C₁₄-aryl and the C₆-C₁₄-aryl in the         C₆-C₁₄-aryl-C₁-C₄-alkyl moiety in each case is unsubstituted or         substituted by one to five substituents selected from the group         consisting of halogen, C₁-C₄-alkyl, phenyl, C₁-C₄-haloalkyl,         C₁-C₄-alkoxy and C₁-C₄-haloalkoxy, or

-   R¹⁶ and R¹⁷ together with the phosphorus atom to which they are     bonded, form a phospholane ring, which may be substituted with one     or two C₁-C₆-alkyl groups.

In the most preferred embodiment of the process according to the invention, the substituents of formulae (Ia), (Ib), (II), (IIIa), (IIIb), (IVa), (IVb) are defined as follows:

-   R¹ is C₁-C₄-alkyl, -   R² and R³ are methyl, -   R⁴ is C₁-C₄-alkyl, -   n is 0 or 1 -   R⁵ if present, is fluorine, -   R⁶ phenyl, 2,6- or 3,5-dimethylphenyl, 2,4,6-trimethylphenyl,     4-tert-butylphenyl, 4-methoxyphenyl,     3,5-bis-tert-butyl-4-methoxyphenyl, 4-tert-butyl-2,6-dimethylphenyl,     4-fluorophenyl, 4-trifluoromethylphenyl, 1-naphtyl, 9-antracenyl     2,4,6-triisopropylphenyl, 9-phenantryl or     2,6-diethyl-4-methylphenyl, -   R⁷ is hydrogen, -   R⁸ is hydrogen or methyl, -   R⁹ and R¹⁰ are each the same and selected from the group consisting     of ethyl, iso-propyl, tert-butyl, cyclopentyl, adamantyl and     cyclohexyl, -   m is 1 or 2, -   A is

-   -   where the bond identified by “*” is bonded directly to the         phosphorus atom and where the bond identified by “#” is bonded         directly to the oxazoline moiety,

-   R¹³ is tert-butyl, iso-propyl or phenyl,

-   R¹⁴ and R¹⁵ are methyl,

-   R¹⁶ and R¹⁷ are each the same and 2-methylphenyl or     3,5-bismethylphenyl.

In a preferred embodiment of the process according to the invention, the ligand of the formula (IIIa) or (IIIb) is used. Depending on whether compound (Ia) or (Ib) is the desired product, the ligand of the formula (IIIa) or (IIIb) is selected.

Preferred are ligands of the formulae (IIIa) and (IIIb), wherein the substituents are defined as follows:

-   R⁶ is C₁-C₆-alkyl, C₁-C₆-haloalkyl, C₃-C₇-cycloalkyl or C₆-C₁₄-aryl,     -   wherein the C₆-C₁₄-aryl is unsubstituted or substituted by one         to five substituents selected from the group consisting of         halogen, C₁-C₄-alkyl, C₁-C₄-haloalkyl, C₁-C₄-alkoxy,         C₁-C₄-haloalkoxy and phenyl, wherein the phenyl again is         unsubstituted or substituted by one to five C₁-C₆-alkyl         substituents, -   R⁷ and R⁸ are independently from one another selected from the group     consisting of hydrogen, C₁-C₆-alkyl, C₁-C₆-alkoxy, C₆-C₁₄-aryl or     C₁-C₆-haloalkyl,     -   wherein the C₆-C₁₄-aryl is unsubstituted or substituted by one         to five C₁-C₄-alkyl substituents, -   R⁹ and R¹⁰ are independently from one another selected from the     group consisting of C₁-C₆-alkyl, C₁-C₆-alkoxy, di(C₁-C₆-alkyl)amino,     C₃-C₁₂-cycloalkyl, C₆-C₁₄-aryl, C₆-C₁₄-aryloxy and     C₆-C₁₄-aryl-C₁-C₄-alkyl,     -   wherein the C₁-C₆-alkyl, C₁-C₆-alkoxy and di(C₁-C₆-alkyl)amino         moieties are optionally substituted by 1 to 3 substituents         independently selected from the group consisting of halogen,         C₁-C₄-alkoxy, C₁-C₄-haloalkyl, C₁-C₄-haloalkoxy and phenyl,         wherein the phenyl may be substituted by one to five         substituents selected independently from each other from         halogen, C₁-C₄-alkyl, C₁-C₄-alkoxy, C₁-C₄-haloalkyl, and         C₁-C₄-haloalkoxy, and     -   wherein the C₆-C₁₄-aryloxy, C₃-C₁₂-cycloalkyl and C₆-C₁₄-aryl,         as such or as part of a composite substituent, in each case is         unsubstituted or substituted by one to five substituents         selected from the group consisting of halogen, C₁-C₄-alkyl,         C₁-C₄-haloalkyl, C₁-C₄-alkoxy, C₁-C₄-haloalkoxy and phenyl,         wherein the phenyl is unsubstituted or substituted by one to         five C₁-C₆-alkyl substituents or -   R⁹ and R¹⁰ together with the phosphorus atom to which they are     bonded, form a phospholane ring, which may be substituted with one     or two C₁-C₆-alkyl groups, and -   m is 1 or 2.

More preferred are ligands of the formulae (IIIa) and (IIIb), wherein the substituents are defined as follows:

-   R⁶ is selected from the group consisting of 1-naphtyl, 2-naphtyl,     9-antracenyl, 9-phenantryl or phenyl, which is unsubstituted or     substituted by one to five substituents selected from the group     consisting of halogen, C₁-C₄-alkoxy, C₁-C₄-alkyl, C₁-C₄-haloalkyl     and phenyl, wherein the phenyl again is unsubstituted or substituted     by one to five C₁-C₆-alkyl substituents, -   R⁷ and R⁸ are independently from one another hydrogen or     C₁-C₆-alkyl, -   R⁹ and R¹⁰ are independently from one another selected from the     group consisting of ethyl, iso-propyl, sec-butyl, iso-butyl,     tert-butyl, cyclohexyl, cyclopentyl, adamantyl and benzyl, and -   m is 1 or 2.

Most preferred are ligands of the formulae (IIIa) and (IIIb), wherein the substituents are defined as follows:

-   R⁶ is selected from the group consisting of, phenyl, 2,6- or     3,5-dimethylphenyl, 2,4,6-trimethylphenyl, 4-tert-butylphenyl,     4-methoxyphenyl, 3,5-bis-tert-butyl-4-methoxyphenyl,     4-tert-butyl-2,6-dimethylphenyl, 4-fluorophenyl,     4-trifluoromethylphenyl, 1-naphtyl, 9-antracenyl     2,4,6-triisopropylphenyl, 9-phenantryl or     2,6-diethyl-4-methylphenyl, -   R⁷ is hydrogen -   R⁸ is hydrogen or methyl, -   R⁹ and R¹⁰ are each the same and tert-butyl, cyclopentyl or     cyclohexyl, and -   m is 1.

In another preferred embodiment of the process according to the invention, the ligand of the formula (IVa) or (IVb) is used. Depending on whether compound (Ia) or (Ib) is the desired product, the ligand of the formula (IVa) or (IVb) is selected.

Preferred are ligands of the formulae (IVa) and (IVb), wherein the substituents are defined as follows:

-   A is

-   -   where the bond identified by “*” is bonded directly to the         phosphorus atom and where the bond identified by “#” is bonded         directly to the oxazoline moiety,

-   R¹³ is C₃-C₆-alkyl, C₃-C₁₂-cycloalkyl, C₆-C₁₄-aryl or     C₆-C₁₄-aryl-C₁-C₄-alkyl,     -   wherein the C₆-C₁₄-aryl and the C₆-C₁₄-aryl in the         C₆-C₁₄-aryl-C₁-C₄-alkyl moiety in each case is unsubstituted or         substituted by one to five substituents selected from the group         consisting of halogen, C₁-C₄-alkyl, C₁-C₄-haloalkyl,         C₁-C₄-alkoxy and C₁-C₄-haloalkoxy,

-   R¹⁴ and R¹⁵ are independently from one another selected from the     group consisting of C₁-C₆-alkyl, C₆-C₁₄-aryl, C₃-C₁₂-cycloalkyl, and     C₆-C₁₄-aryl-C₁-C₄-alkyl,     -   wherein C₆-C₁₄-aryl and the C₆-C₁₄-aryl in the         C₆-C₁₄-aryl-C₁-C₄-alkyl moiety is unsubstituted or substituted         by one to five substituents selected from the group consisting         of halogen, C₁-C₄-alkyl, C₁-C₄-haloalkyl, C₁-C₄-alkoxy and         C₁-C₄-haloalkoxy, or

-   R¹⁴ and R¹⁵ together with the carbon to which they are bonded, form     a C₅-C₆-cycloalkyl ring,

-   R¹⁶ and R¹⁷ are independently from one another selected from the     group consisting of C₁-C₆-alkyl, C₃-C₁₂-cycloalkyl, C₆-C₁₄-aryl and     C₆-C₁₄-aryl-C₁-C₄-alkyl,     -   wherein the C₁-C₆-alkyl is optionally substituted by 1 to 3         substituents independently selected from the group consisting of         halogen, C₁-C₄-alkoxy, C₁-C₄-haloalkyl, C₁-C₄-haloalkoxy and         phenyl, wherein the phenyl may be substituted by one to five         substituents selected independently from each other from         halogen, C₁-C₄-alkyl, C₁-C₄-alkoxy, C₁-C₄-haloalkyl, and         C₁-C₄-haloalkoxy, and     -   wherein the C₆-C₁₄-aryl and the C₆-C₁₄-aryl in the         C₆-C₁₄-aryl-C₁-C₄-alkyl moiety in each case is unsubstituted or         substituted by one to five substituents selected from the group         consisting of halogen, C₁-C₄-alkyl, phenyl, C₁-C₄-haloalkyl,         C₁-C₄-alkoxy and C₁-C₄-haloalkoxy, or

-   R¹⁶ and R¹⁷ together with the phosphorus atom to which they are     bonded, form a phospholane ring, which may be substituted with one     or two C₁-C₆-alkyl groups.

More preferred are ligands of the formulae (IVa) and (IVb), wherein the substituents are defined as follows:

-   A is

-   -   where the bond identified by “*” is bonded directly to the         phosphorus atom and where the bond identified by “#” is bonded         directly to the oxazoline moiety,

-   R¹³ is iso-propyl, sec-butyl, iso-butyl, tert-butyl, phenyl or     benzyl,

-   R¹⁴ and R¹⁵ are independently from one another selected from the     group consisting of C₁-C₆-alkyl, and C₆-aryl-C₁-C₄-alkyl,     -   wherein the C₆-aryl in the C₆-C₁₄-aryl-C₁-C₄-alkyl moiety is         unsubstituted or substituted by one to five substituents         selected from the group consisting of halogen and C₁-C₄-alkyl,

-   R¹⁶ and R¹⁷ are independently from one another phenyl, 1-naphthyl or     2-naphthyl, which in each case is unsubstituted or substituted by     one to five C₁-C₄-alkyl substituents

Most preferred are ligands of the formulae (IVa) and (IVb), wherein the substituents are defined as follows:

-   A is

-   -   where the bond identified by “*” is bonded directly to the         phosphorus atom and where the bond identified by “#” is bonded         directly to the oxazoline moiety,

-   R¹³ is tert-butyl,

-   R¹⁴ and R¹⁵ are methyl, and

-   R¹⁶ and R¹⁷ are independently from one another phenyl, which is     substituted by one or two methyl, in particular R¹⁶ and R¹⁷ are each     the same and phenyl, which is substituted by one or two methyl or     R¹⁶ and R¹⁷ are each the same and 2-methylphenyl or     3,5-dimethylphenyl.

Preferably, the chiral iridium catalyst is selected from the group consisting of [IrL*(COD)]Y and [IrL*(nbd)]Y, wherein

-   L* is the chiral ligand of the formula (IIIa), (IIIb), (IVa) or     (IVb), -   COD represents 1,5-cyclooctadiene, -   nbd represents norbornadiene, and -   Y is a non-coordinating anion selected from the group consisting of     [B(R¹⁸)₄]⁻, PF₆ ⁻, SbF₆ ⁻, CF₃SO₃ ⁻, [Al{OC(CF₃)₃}₄]⁻ (VII) and     Δ-TRISPHAT (VIII)

-   -   wherein R¹⁸ is selected from fluorine and phenyl, which is         unsubstituted or substituted with one to five substituents         selected from C₁-C₄-alkyl, C₁-C₄-haloalkyl and halogen.

More preferred are chiral iridium catalysts of the formulae [IrL*(COD)]Y and [IrL*(nbd)]Y, wherein Y is [Al{OC(CF₃)₃}₄]⁻ (VII) or [B(R¹⁸)₄]⁻, wherein R¹⁸ is phenyl, which is unsubstituted or substituted with one to five substituents selected from fluorine and trifluoromethyl.

Even more preferred are chiral iridium catalysts of the general formulae (Va), (Vb), (VIa) and (VIb)

wherein

-   R⁶ is selected from the group consisting of 1-naphtyl, 2-naphtyl,     9-antracenyl, 9-phenantryl or phenyl,     -   wherein 1-naphtyl, 2-naphtyl, 9-antracenyl, 9-phenantryl and         phenyl are unsubstituted or substituted by one to five         substituents selected from the group consisting of halogen,         C₁-C₄-alkoxy, C₁-C₄-alkyl, C₁-C₄-haloalkyl and phenyl, wherein         the phenyl again is unsubstituted or substituted by one to five         C₁-C₆-alkyl substituents, -   R⁷ and R⁸ are independently from one another hydrogen, C₁-C₆-alkyl     or C₁-C₆-alkoxy -   R⁹ and R¹⁰ are independently from one another selected from the     group consisting of ethyl, iso-propyl, sec-butyl, iso-butyl,     tert-butyl, cyclohexyl, cyclopentyl, adamantyl and benzyl, -   m is 1 or 2, -   R¹³ is iso-propyl, sec-butyl, iso-butyl, tert-butyl, phenyl or     benzyl, -   R¹⁴ and R¹⁵ are independently from one another selected from the     group consisting of C₁-C₆-alkyl, and C₆-aryl-C₁-C₄-alkyl,     -   wherein the C₆-aryl in the C₆-C₁₄-aryl-C₁-C₄-alkyl moiety is         unsubstituted or substituted by one to five substituents         selected from the group consisting of halogen and C₁-C₄-alkyl, -   R¹⁶ and R¹⁷ are independently from one another phenyl, 1-naphthyl or     2-naphthyl, which in each case is unsubstituted or substituted by     one to five substituents selected from the group consisting of     halogen, C₁-C₄-alkyl and C₁-C₄-haloalkyl, and -   R¹⁸ is phenyl, which is unsubstituted or substituted with one to     five substituents selected from fluorine and C₁-C₄-haloalkyl.

Particularly preferred are chiral iridium catalysts of the general formulae (Va), (Vb), (VIa) and (VIb), wherein

-   R⁶ is selected from the group consisting of phenyl, 2,6- or     3,5-dimethylphenyl, 2,4,6-trimethylphenyl, 4-tert-butylphenyl,     4-methoxyphenyl, 3,5-bis-tert-butyl-4-methoxyphenyl,     4-tert-butyl-2,6-dimethylphenyl, 4-fluorophenyl,     4-trifluoromethylphenyl, 1-naphtyl, 9-antracenyl,     2,4,6-triisopropylphenyl, 9-phenantryl and     2,6-diethyl-4-methylphenyl, -   R⁷ is hydrogen, -   R⁸ is hydrogen or methyl -   R⁹ and R¹⁰ are each the same and tert-butyl, adamantly, cyclopentyl     or cyclohexyl, -   m is 1 or 2, -   R¹³ is tert-butyl, -   R¹⁴ and R¹⁵ are methyl, -   R¹⁶ and R¹⁷ are independently from one another phenyl, which is     substituted by one or two methyl, in particular R¹⁶ and R¹⁷ are each     the same and 2-methylphenyl or 3,5-dimethylphenyl, and -   R¹⁸ is 3,5-bis(trifluoromethyl)phenyl.

In an alternative embodiment the chiral iridium catalysts is of the general formulae (Va) and (Vb), wherein

-   R⁶ is selected from the group consisting of phenyl, 2,6- or     3,5-dimethylphenyl, 2,4,6-trimethylphenyl, 4-tert-butylphenyl,     4-methoxyphenyl, 3,5-bis-tert-butyl-4-methoxyphenyl,     4-tert-butyl-2,6-dimethylphenyl, 4-fluorophenyl,     4-trifluoromethylphenyl, 1-naphtyl, 9-antracenyl,     2,4,6-triisopropylphenyl, 9-phenantryl and     2,6-diethyl-4-methylphenyl, -   R⁷ is hydrogen -   R⁸ is C₁-C₆-alkoxy -   R⁹ and R¹⁰ are independently from one another selected from the     group consisting of ethyl, iso-propyl, sec-butyl, iso-butyl,     tert-butyl, cyclohexyl, cyclopentyl, adamantyl and benzyl, and -   m is 1.

The amount of iridium catalyst used is preferably within the range of from 0.001 mol % to 5 mol %, more preferably 0.005 mol % to 4 mol %, most preferably 0.01 mol % to 3 mol %, in particular 0.01 mol % to 2.0 mol %, based on the amount of the compound of the formula (II).

The chiral iridium catalyst may be prepared by methods known in the art from an iridium (I) catalyst precursor, such as [Ir(COD)Cl]₂, the chiral ligand of the formula (IIIa), (IIIb), (IVa) or (IVb) and an alkali salt of the non-coordinating anion (S. Kaiser et al., Angew. Chem. Int. Ed. 2006, 45, 5194-5197; W. J. Drury III et al., Angew. Chem. Int. Ed. 2004, 43, 70-74).

The process according to the invention comprises enantioselective hydrogenation of the compound of the formula (II).

Preferably, the hydrogenation is conducted using hydrogen gas at a pressure of from 1 to 300 bar, preferably 3 to 200 bar, most preferably 20 to 150 bar.

The hydrogenation is preferably conducted at a temperature within the range of from 20° C. to 130° C., more preferably 30° C. to 100° C.

Suitable solvents are halogenated alcohols such as 2,2,2,-trifluoroethanol, hexafluoroisopropanol (1,1,1,3,3,3-hexafluoro-2-propanol) and tetrafluoropropanol (2,2,3,3-tetrafluoro-1-propanol), halogenated hydrocarbons, such as chlorobenzene, dichlorobenzene, dichloromethane, chloroform, tetrachloromethane, dichloroethane and trichloroethane, aromatic hydrocarbons such as benzene, toluene and xylene, ethers such as diethyl ether, diisopropyl ether, methyl tert-butyl ether, methyl tert-amyl ether, dioxane, tetrahydrofuran, 1,2-dimethoxyethane, 1,2-diethoxyethane and anisole, and esters such as ethyl acetate, isopropyl acetate, and mixtures thereof.

Preferred solvents are selected from the group consisting of 2,2,2,-trifluoroethanol, hexafluoroisopropanol, 1,2-dichloroethane, tetrafluoropropanol, 1,4-dioxane, isopropyl acetate, toluene, and mixtures thereof.

More preferred solvents are selected from the group consisting of 2,2,2,-trifluoroethanol, hexafluoroisopropanol, 1,2-dichloroethane, tetrafluoropropanol, and mixtures thereof.

Especially preferred are 2,2,2,-trifluoroethanol and hexafluoroisopropanol.

Most preferred is hexafluoroisopropanol.

The hydrogenation may optionally be conducted in presence of an acidic additive, such as acetic acid, trifluoroacetic acid, camphorsulfonic acid, p-toluenesulfonic acid, pivalic acid, benzoic acid, formic acid, butyric acid or oxalic acid. If an acidic additive is used, it is preferably used as a mixture with the solvent.

The amount of acidic used is preferably at most 20 mol %, more preferably at most 10 mol %, and in particular within the range of from 0 to 5 mol %, based on the amount of the compound of the formula (II).

Preparation of Iridium Catalysts

The ligand precursors (enantiomerically enriched secondary alcohols) were prepared according to known literature procedures like to the method disclosed in S. Kaiser et al., Angew. Chem. Int. Ed. 2006, 45, 5194-5197 or in D. H. Woodmansee Chem. Sci 2010, 1, 72. The ligands and Iridium complexes were prepared by a modified procedure based on the same literature precedents:

Procedure of ligand synthesis (under Ar): A solution of alcohol precursor in THE (0.25 mmol, in 5.0 mL THF) was cooled to −78° C. and n-BuLi (0.1 mL of a 2.5 M n-BuLi solution in hexane; 0.25 mmol; 1 eq.) was added dropwise to the continuously stirred solution. After completion of the addition the solution was allowed to warm to room temperature and was stirred at this temperature for further 30 min. The solution was cooled to −78° C. again and R₂PCl (0.25 mmol, 1 eq.) was added to the continuously stirred solution. The mixture was allowed to warm to room temperature and subsequently heated to 50° C. and kept at this temperature overnight. The theoretical yield of ligand was calculated using ³¹P-NMR and the ligand was used for the next step without further purification.

Procedure of complexation (under Ar): To the crude ligand solution was added [Ir(COD)₂]BARF (BARF=Tetrakis[3,5-bis(trifluoromethyl)phenyl]-borate) (as a solid, 1 eq. based on the theoretical yield). The resulting mixture was heated to 50° C. and kept at this temperature for 3 h.

Work-up (under air): After cooling to room temperature the reaction solution is rotary evaporated onto silica, loaded onto a column of silica. Side components were eluted using pentane/diethylether and the desired complexes subsequently with DCM. The solvent was then evaporated under reduced pressure.

The following specified catalysts were synthesized and characterized:

with m=1 and R¹⁸=3,5-bis(trifluoromethyl)phenyl

Catalyst R⁶ R⁷ R⁸ R⁹, R¹⁰ Va-1 phenyl H H tert-butyl Va-2 phenyl H methyl tert-butyl Vb-3 phenyl H H cyclohexyl Va-4 phenyl H methyl cyclohexyl Vb-5 4-tert-butylphenyl H H cyclohexyl Va-6 4-tert-butylphenyl H methyl cyclohexyl Vb-7 9-antracenyl H H cyclohexyl Va-8 9-antracenyl H methyl cyclohexyl Va-9 2,6-dimethylphenyl H methyl cyclohexyl Va-10 2,4,6-trimethylphenyl H methyl cyclohexyl Va-11 3,5-dimethylphenyl H methyl cyclohexyl Va-12 1-naphtyl H methyl cyclohexyl Va-13 4-methoxyphenyl H methyl tert-butyl Va-14 4-fluorophenyl H methyl tert-butyl Va-15 4-(trifluoromethyl)phenyl H methyl tert-butyl Va-16 phenyl H methyl cyclopentyl Vb-17 phenyl H H ethyl Va-18 phenyl H methyl isopropyl Va-19 methyl H methyl cyclohexyl Va-20 3,5-bis-tert.-butyl,-4- H methyl cyclohexyl methoxyphenyl Va-21 2,4,6-triisopropylphenyl H methyl cyclohexyl Va-22 4-tert-butyl-2,6- H methyl cyclohexyl dimethylphenyl Va-23 phenyl H H adamantyl

Va-2

The reaction was performed according to the above described procedure. The complex could be isolated as an orange solid (89.5 mg; 53% based on [Ir(COD)₂]BARF).

¹H-NMR (300 MHz, CD₂Cl₂): δ (ppm)=8.26 (dd, J=7.9, 1.7 Hz, 2H), 7.81-7.36 (in, 16H), 5.75 (dt, J=8.0, 5.2 Hz, 1H), 5.34-5.29 (in, 1H), 4.51 (q, J=5.3, 3.2 Hz, 1H), 4.11 (dq, J=12.5, 7.6, 5.9 Hz, 1), 3.08 (ddd, J=16.6, 10.3, 3.8 Hz, 1H), 2.99-2.70 (i, 2H), 2.61-2.00 (m, 8H), 1.92-1.79 (i, 1H), 1.69 (dd, J=14.8, 8.1 Hz, 1H), 1.51 (s, 9H), 1.29-1.24 (i, 3H), 1.06 (d, J=14.4 Hz, 9H). ³¹P-NMR (122 MHz, CD₂Cl₂) δ (ppm)=142.09. ¹⁹F-NMR (282 MHz, CD₂Cl₂) δ (ppm)=−62.85. HR-MS (ESI) m/z calcd for C₃₁H₄₄NOPIr [M]+ 670.2790 found 670.2798.

Va-4

The reaction was performed according to the above described procedure. The complex could be isolated as an orange solid (241 mg; 71% based on [Ir(COD)₂]BARF).

¹H-NMR (300 MHz, CD₂Cl₂): δ (ppm)=8.38-8.14 (m, 2H), 7.83-7.43 (m, 16H), 5.76 (dt, J=7.7, 4.9 Hz, 1H), 4.81 (t, J=7.6 Hz, 1H), 4.70-4.46 (m, 1H), 3.56-3.39 (m, 1H), 3.06 (ddd, J=16.7, 10.3, 3.6 Hz, 1H), 2.98-2.73 (m, 2H), 2.71-2.57 (m, 1H), 2.44 (s, 3H), 2.41-2.02 (m, 6H), 2.00-1.75 (m, 7H), 1.72-1.54 (m, 4H), 1.46-0.94 (m, 13H), 0.72-0.50 (m, 1H). ³¹P-NMR (122 MHz, CD₂Cl₂) δ (ppm)=121.27. ¹⁹F-NMR (282 MHz, CD₂Cl₂) δ (ppm)=−62.86. HR-MS (ESI) m/z calcd for C₃₅H₄₈NOPIr [M]+ 722.3103 found 722.3116.

Vb-5

The reaction was performed according to the above described procedure using 287 mg of [Ir(COD)₂]BARF (0.225 mmol). The complex could be isolated as an orange solid (261 mg; 74% based on [Ir(COD)₂]BARF).

¹H-NMR (300 MHz, CD₂Cl₂): δ (ppm)=8.25 (d, J=8.3 Hz, 2H), 7.87 (d, J=8.1 Hz, 1H), 7.81-7.64 (m, 111H), 7.56 (s, 4H), 5.74 (dt, J=8.2, 4.6 Hz, 1H), 4.95-4.74 (m, 1H), 4.74-4.51 (m, 1H), 3.60-3.45 (m, 1H), 3.23-2.91 (m, 2H), 2.90-2.70 (m, 1H), 2.67-2.50 (m, 1H), 2.52-2.23 (m, 4H), 2.28-2.04 (m, 3H), 2.04-1.77 (m, 7H), 1.69-1.58 (m, 4H), 1.45-1.26 (m, 17H), 1.17-0.95 (m, 4H), 0.68-0.42 (m, 1H). ³¹P-NMR (122 MHz, CD₂Cl₂) δ (ppm)=121.12. ¹⁹F-NMR (282 MHz, CD₂Cl₂) δ (ppm)=−62.85.

HR-MS (ESI) m/z calcd for C₃₈H₅₄NOPIr [M]+ 764.3572 found 764.3586.

Va-6

The reaction was performed according to the above described procedure. The complex could be isolated as an orange solid (286 mg; 64% based on [Ir(COD)₂]BARF).

¹H-NMR (300 MHz, CDCl₃): δ (ppm)=8.20 (d, J=8.2 Hz, 2H), 7.77-7.69 (m, 8H), 7.66 (d, J=8.4 Hz, 2H), 7.53 (d, J=4.9 Hz, 5H), 5.77-5.67 (m, 1H), 4.78 (d, J=7.6 Hz, 1H), 4.57 (s, 1H), 3.47 (s, 1H), 3.08-2.89 (m, 1H), 2.89-2.66 (m, 2H), 2.59 (p, J=7.4 Hz, 1H), 2.47-1.74 (m, 15H), 1.42 (s, 17H), 1.18-0.78 (m, 5H), 0.72-0.48 (m, 1H). ³¹P-NMR (122 MHz, CDCl₃) 121.31. ¹⁹F-NMR (282 MHz, CDCl₃) δ=−62.42. HR-MS (ESI): m/z calculated for [C₃₉H₅₆NOP193Ir]+: 778.3729 found 778.3732.

Vb-7

The reaction was performed according to the above described procedure using 287 mg of [Ir(COD)₂]BARF (0.225 mmol). The complex could be isolated after two time purification as an orange solid (151 mg; 36% based on [Ir(COD)₂]BARF).

¹H-NMR (300 MHz, CD₂Cl₂): δ (ppm)=8.84 (s, 1H), 8.38-8.27 (m, 1H), 8.21 (ddt, J=8.5, 1.3, 0.7 Hz, 1H), 8.18-8.02 (m, 2H), 7.83-7.72 (m, 10H), 7.72-7.54 (m, 6H), 7.49 (ddd, J=8.8, 6.6, 1.4 Hz, 1H), 7.23-6.96 (m, 1H), 5.74-5.54 (m, 1H), 5.26-5.12 (m, 1H), 4.41-4.18 (m, 1H), 3.53-3.15 (m, 3H), 2.75-2.61 (m, 2H), 2.59-2.32 (m, 2H), 2.18-1.91 (m, 6H), 1.92-1.74 (m, 5H), 1.74-1.56 (m, 2H), 1.48-1.21 (m, 10H), 1.18-0.99 (m, 1H), 0.96-0.59 (m, 2H), 0.39-0.15 (m, 1H), 0.06-0.11 (m, 1H). ³¹P-NMR (122 MHz, CD₂Cl₂) δ (ppm)=120.30. ¹⁹F-NMR (282 MHz, CD₂Cl₂) δ (ppm)=−62.87. HR-MS (ESI) m/z calcd for C₄₂H₅₀NOPIr [M]+ 808.3259 found 808.3278.

Va-8

The reaction was performed according to the above described procedure using 287 mg of [Ir(COD)₂]BARF (0.225 mmol). The complex could be isolated using DCM (100%) to afford an orange solid (296 mg; 78% based on [Ir(COD)₂]BARF).

¹H-NMR (300 MHz, CD₂Cl₂): δ (ppm)=8.68 (s, 1H), 8.23-7.85 (m, 3H), 7.75-7.23 (m, 17H), 7.05 (dq, J=8.8, 1.0 Hz, 1H), 5.61-5.40 (m, 2H), 5.12-4.88 (m, 1H), 4.24-4.00 (m, 1H), 3.25-2.88 (m, 3H), 2.58-2.46 (m, 2H), 2.44-2.14 (m, 7H), 2.08-1.61 (m, 111H), 1.61-1.37 (m, 5H), 1.37-1.07 (m, 6H), 1.03-0.85 (m, 1H), 0.65-0.45 (m, 1H), 0.16 (dtd, J=15.8, 10.4, 5.6 Hz, 1H), −0.16 (dt, J=13.2, 9.1 Hz, 1H). ³¹P-NMR (122 MHz, CD2Cl2) δ=120.57. ¹⁹F-NMR (282 MHz, CD2Cl2) δ=−62.86. HR-MS (ESI) m/z calcd for C₄₃H₅₂NOPIr [M]+ 822.3416 found 822.3416.

Va-9

The reaction was performed according to the above described procedure using 287 mg of [Ir(COD)₂]BARF (0.225 mmol). The complex could be isolated as an orange solid (298 mg; 82% based on [Ir(COD)₂]BARF).

¹H-NMR (300 MHz, CD₂Cl₂): δ (ppm)=7.80-7.52 (m, 12H), 7.42-7.19 (m, 3H), 7.12 (d, J=7.5 Hz, 1H), 5.65 (td, J=5.6, 2.6 Hz, 1H), 5.48-5.42 (m, 1H), 4.43-4.37 (m, 1H), 3.38-3.30 (m, 1H), 3.21-2.89 (m, 3H), 2.67 (s, 3H), 2.58-2.45 (m, 2H), 2.42 (s, 3H), 2.38-2.16 (m, 2H), 2.13-2.05 (m, 3H), 2.02-1.89 (m, 4H), 1.84 (s, 3H), 1.81-1.72 (m, 2H), 1.64-1.49 (m, 3H), 1.39-1.19 (m, 8H), 1.12-0.99 (m, 4H), 0.68-0.56 (m, 1H). ³¹P-NMR (122 MHz, CD₂Cl₂) δ=118.80. ¹⁹F-NMR (282 MHz, CD₂Cl₂) δ=−62.88. HR-MS (ESI) m/z calcd for CH₅₂NOPIr [M]+ 750.3416 found 750.3420.

Va-10

The reaction was performed according to the above described procedure using 287 mg of [Ir(COD)₂]BARF (0.225 mmol). The complex could be isolated as an orange solid (148 mg; 40% based on [Ir(COD)₂]BARF).

¹H-NMR (300 MHz, CD₂Cl₂): δ (ppm)=7.91-7.46 (m, 12H), 7.21 (s, 1H), 7.09 (s, 1H), 6.94 (s, 1H), 5.67-5.63 (m, 1H), 5.46-5.41 (m, 1H), 4.38-4.36 (m, 1H), 3.36-3.32 (m, 1H), 3.19-2.85 (m, 3H), 2.64 (s, 3H), 2.53-2.46 (m, 2H), 2.41 (s, 3H), 2.35 (s, 3H), 2.31-2.18 (m, 2H), 2.19-1.83 (m, 14H), 1.68-1.54 (m, 6H), 1.38-1.20 (m, 5H), 1.14-0.97 (m, 5H), 0.68-0.56 (m, 1H). ³¹P-NMR (122 MHz, CD₂Cl₂) δ=118.64. ¹⁹F-NMR (282 MHz, CD₂Cl₂) δ=−62.87. HR-MS (ESI) m/z calcd for C₃₈H₅₄NOPIr [M]+ 764.3572 found 764.3577.

Va-11

The reaction was performed according to the above described procedure using 287 mg of [Ir(COD)₂]BARF (0.225 mmol). The complex could be isolated using DCM (100%) to afford an orange solid (310 mg; 85% based on [Ir(COD)₂]BARF).

¹H-NMR (300 MHz, CD₂Cl₂): δ (ppm)=7.86 (s, 2H), 7.79-7.47 (m, 13H), 7.36 (s, 1H), 5.79-5.62 (m, 1H), 4.78-4.74 (m, 1H), 4.57-4.53 (m, 1H), 3.56-3.48 (m, 1H), 3.13-2.95 (m, 1H), 2.95-2.61 (m, 3H), 2.51 (s, 6H), 2.47-2.36 (m, 5H), 2.34-2.03 (m, 5H), 2.03-1.77 (m, 7H), 1.71-1.47 (m, 7H), 1.45-1.19 (m, 5H), 1.19-0.98 (m, 4H), 0.70-0.62 (m, 1H). ³¹P-NMR (122 MHz, CD₂Cl₂) δ=121.65. ¹⁹F-NMR (282 MHz, CD₂Cl₂) δ=−62.88. HR-MS (ESI) m/z calcd for C₃₇H₅₂NOPIr [M]+ 750.3416 found 750.3406.

Va-12

The reaction was performed according to the above described procedure using 287 mg of [Ir(COD)₂]BARF (0.225 mmol). The complex could be isolated as an orange solid (286 mg; 78% based on [Ir(COD)₂]BARF).

¹H-NMR (300 MHz, CD₂Cl₂): δ (ppm)=8.61-8.48 (m, 1H), 8.28-8.15 (m, 1H), 8.11-7.98 (m, 1H), 7.98-7.81 (m, 1H), 7.79-7.50 (m, 16H), 5.70 (ddd, J=8.1, 4.9, 3.2 Hz, 1H), 5.37-5.25 (m, 1H), 4.79 (d, J=10.4 Hz, 1H), 3.53-3.41 (m, 1H), 3.13 (ddd, J=17.2, 9.5, 4.9 Hz, 1H), 2.96 (ddd, J=17.1, 9.4, 4.9 Hz, 1H), 2.88-2.66 (m, 1H), 2.49-2.34 (m, 7H), 2.27-2.14 (m, 1H), 2.09-1.56 (m, 15H), 1.43-1.12 (m, 9H), 1.06-0.92 (m, 1H), 0.78-0.59 (m, 1H), 0.42-0.25 (m, 1H). ³¹P-NMR (122 MHz, CD₂Cl₂) δ=121.69. ¹⁹F-NMR (282 MHz, CD₂Cl₂) δ=−62.87. HR-MS (ESI) m/z calcd for C₃₉H₅₀NOPIr [M]+ 722.3259 found 722.3262.

Va-13

The reaction was performed according to the above described procedure. The theoretical yield of the ligand was 51%. The complex could be isolated as an orange solid (78.0 mg; 39% based on [Ir(COD)₂]BARF).

¹H-NMR (300 MHz, CDCl₃): δ (ppm)=8.22 (d, J=8.7 Hz, 2H), 7.80-7.63 (m, 8H), 7.63-7.43 (m, 5H), 7.16 (d, J=8.8 Hz, 2H), 5.82-5.66 (m, 1H), 5.37-5.22 (m, 1H), 4.56-4.41 (m, 1H), 4.18-4.00 (m, 1H), 3.93 (s, 3H), 3.12-2.97 (m, 1H), 2.96-2.74 (m, 2H), 2.70-2.56 (m, 1H), 2.43 (s, 3H), 2.41-2.03 (m, 4H), 1.96-1.84 (m, 1H), 1.72 (dd, J=14.6, 7.9 Hz, 1H), 1.51 (d, J=15.0 Hz, 9H), 1.34-1.23 (m, 3H), 1.05 (d, J=14.4 Hz, 9H). ³¹P-NMR (122 MHz, CD₂Cl₂) δ (ppm)=141.86. ¹⁹F-NMR (282 MHz, CD₂Cl₂) δ (ppm)=−62.85. HR-MS (ESI) m/z calcd for C₃₂H₄₆NO₂PIr [M]+ 700.2895 found 700.2899.

Va-14

The reaction was performed according to the above described procedure using 287 mg of [Ir(COD)²]BARF (0.225 mmol). The complex could be isolated as an orange solid (245 mg; 70% based on [Ir(COD)²]BARF).

¹H-NMR (300 MHz, CDCl₃): δ (ppm)=8.38-8.12 (m, 2H), 7.82-7.63 (m, 8H), 7.51 (s, 5H), 7.44-7.17 (m, 2H), 5.81-5.63 (m, 1H), 4.81-4.67 (m, 1H), 4.67-4.49 (m, 1H), 3.57-3.35 (m, 1H), 3.05-2.90 (m, 1H), 2.88-2.61 (m, 3H), 2.36 (s, 3H), 2.31-2.04 (m, 7H), 2.01-1.73 (m, 7H), 1.70-1.48 (m, 6H), 1.42-1.20 (m, 6H), 1.16-0.97 (m, 4H), 0.63-0.40 (m, 1H). ³¹P-NMR (122 MHz, CDCl₃) δ (ppm)=121.31. ¹⁹F-NMR (282 MHz, CDCl₃) δ (ppm)=−62.43, −106.61. HR-MS (ESI) m/z calcd for C₃₅H₄₇NOFPIr [M]+ 740.3009 found 740.3013.

Va-15

The reaction was performed according to the above described procedure using 287 mg of [Ir(COD)₂]BARF (0.225 mmol). The complex could be isolated as an orange solid (180.0 mg; 48% based on [Ir(COD)₂]BARF).

¹H-NMR (300 MHz, CD₂Cl₂): δ (ppm)=8.46 (d, J=7.9 Hz, 2H), 7.94 (d, J=8.0 Hz, 2H), 7.82-7.38 (m, 13H), 5.83-5.69 (m, 1H), 4.94-4.78 (m, 1H), 4.73-4.54 (m, 1H), 3.65-3.38 (m, 1H), 3.15-2.72 (m, 3H), 2.61-2.27 (m, 7H), 2.25-2.04 (m, 4H), 2.04-1.72 (m, 8H), 1.75-1.58 (m, 3H), 1.43-1.22 (m, 8H), 1.19-0.93 (m, 1H), 0.63-0.44 (m, 1H). ³¹P-NMR (122 MHz, CD₂Cl₂) δ (ppm)=121.74. ¹⁹F-NMR (282 MHz, CD₂Cl₂) δ (ppm)=−62.88, −63.40. HR-MS (ESI) m/z calcd for C₃₆H₄₇NOF₃PIr [M]+ 790.2977 found 790.2990.

Va-16

The reaction was performed according to the above described procedure. The theoretical yield of the ligand was 90%. The complex could be isolated as an orange solid (261 mg; 75% based on [Ir(COD)₂]BARF).

¹H-NMR (300 MHz, CD₂Cl₂): δ (ppm)=8.28-8.11 (m, 2H), 7.93-7.45 (m, 16H), 5.81 (dt, J=9.3, 5.0 Hz, 1H), 4.89 (t, J=6.9 Hz, 1H), 4.72-4.51 (m, 1H), 3.86-3.66 (m, 1H), 3.18-3.04 (m, 1H), 3.04-2.57 (m, 4H), 2.49 (s, 3H), 2.46-1.61 (m, 18H), 1.56-1.36 (m, 5H), 1.36-1.14 (m, 1H), 1.13-0.93 (m, 1H), 0.77-0.66 (m, 1H). ³¹P-NMR (122 MHz, CD₂Cl₂) δ (ppm)=129.37. ¹⁹F-NMR (282 MHz, CD₂Cl₂) δ (ppm)=−62.88. HR-MS (ESI) m/z calcd for C₃₃H₄₄NOPIr [M]+ 694.2790 found 694.2789.

Vb-17

The reaction was performed according to the above described procedure. The complex could be isolated as an orange solid (134 mg; 95% purity based on 31P-NMR; 39% based on [Ir(COD)₂]BARF).

¹H-NMR (300 MHz, CDCl₃): δ (ppm)=8.00-7.92 (m, 2H), 7.81-7.76 (m, 1H), 7.75-7.64 (m, 10H), 7.62-7.55 (m, 2H), 7.52 (d, J=1.9 Hz, 4H), 5.88 (dt, J=8.3, 4.9 Hz, 1H), 4.52 (dt, J=8.3, 4.2 Hz, 1H), 4.37 (ddt, J=7.4, 5.0, 2.5 Hz, 1H), 3.61 (td, J=8.0, 3.8 Hz, 1H), 3.17-2.64 (m, 4H), 2.34-1.79 (m, 9H), 1.68-1.55 (m, 1H), 1.36-0.90 (m, 9H). ³¹P-NMR (122 MHz, CDCl₃) δ=116.36 (mayor product; 95%), 111.79 (minor species; 5%). ¹⁹F-NMR (282 MHz, CDCl₃) δ=−62.41. HR-MS (ESI) m/z calcd for C₂H₃₄NOPIr [M]+ 600.2006 found 600.2006.

Va-18

The reaction was performed (0.5 mmol scale) according to the above described procedure, but after the addition of ClP(iPr)₂ was completed, the reaction mixture was stirred at RT for 16 h. The complex could be isolated as an orange solid (605 mg; 85% based on [Ir(COD)₂]BARF).

¹H-NMR (300 MHz, CDCl₃): δ (ppm)=8.17 (dd, J=7.1, 1.8 Hz, 2H), 7.78-7.40 (m, 16H), 5.74 (dt, J=9.0, 4.7 Hz, 1H), 4.83 (t, J=6.9 Hz, 1H), 4.61 (dt, J=8.7, 4.1 Hz, 1H), 3.62-3.53 (m, 1H), 3.11-2.94 (m, 1H), 2.91-2.67 (m, 2H), 2.67-2.44 (m, 2H), 2.39 (s, 3H), 2.36-1.93 (m, 6H), 1.85 (dd, J=14.5, 7.3 Hz, 1H), 1.46 (dd, J=15.2, 7.1 Hz, 3H), 1.39-1.31 (m, 1H), 1.23 (dd, J=13.3, 6.9 Hz, 4H), 1.08 (dd, J=19.4, 7.1 Hz, 3H), 0.52 (dd, J=15.5, 7.1 Hz, 3H). ³¹P-NMR (122 MHz, CDCl₃) δ (ppm)=129.53. ¹⁹F-NMR (282 MHz, CDCl₃) δ (ppm)=−62.42. HR-MS (ESI) m/z calcd for C₂₉H₄₀NOPIr [M]+ 642.2477 found 642.2480.

Va-19

The reaction was performed according to the above described procedure. The complex could be isolated as an orange solid (249 mg; 73% based on [Ir(COD)₂]BARF).

¹H-NMR (300 MHz, CD₂Cl₂): δ (ppm)=7.81-7.61 (m, 9H), 7.56 (d, J=2.0 Hz, 4H), 7.34 (d, J=8.0 Hz, 1H), 5.76 (dt, J=8.7, 4.5 Hz, 1H), 5.05-4.84 (m, 2H), 3.74-3.57 (m, 1H), 3.56-3.36 (m, 1H), 3.07 (s, 3H), 3.01-1.49 (m, 23H), 1.42-1.01 (m, 9H), 0.85-0.70 (m, 1H), 0.51-0.25 (m, 1H). ³¹P-NMR (122 MHz, CD₂Cl₂) δ (ppm)=126.20. ¹⁹F-NMR (282 MHz, CD₂Cl₂) δ (ppm)=−62.88. HR-MS (ESI) m/z calcd for C₂₉H₄NOPIr [M]+ 644.2766 found 644.2762.

Va-20

The reaction was performed according to the above described procedure. The complex could be isolated as an orange solid (164 mg; 42% based on [Ir(COD)₂]BARF).

¹H-NMR (300 MHz, CD₂Cl₂): δ (ppm)=7.86-7.62 (m, 10H), 7.56 (s, 4H), 7.38 (s, 1H), 5.72 (dt, J=8.1, 5.2 Hz, 1H), 4.85-4.63 (m, 2H), 3.80 (s, 3H), 3.49-3.30 (m, 1H), 3.18-2.60 (m, 4H), 2.54-2.23 (m, 6H), 2.23-1.57 (m, 16H), 1.53-1.49 (m, 20H), 1.46-0.93 (m, 10H). ³¹P-NMR (122 MHz, CD₂Cl₂) δ (ppm)=123.26. ¹⁹F-NMR (282 MHz, CD₂Cl₂) δ (ppm)=−62.87. HR-MS (ESI) m/z calcd for C₄₄H₆₆NO₂PIr [M]+ 864.4460 found 864.4448.

Va-21

The reaction was performed according to the above described procedure. The complex could be isolated as an orange solid (51 mg; 14% based on [Ir(COD)₂]BARF).

¹H-NMR (400 MHz, CD₂Cl₂): δ (ppm)=7.80-7.64 (m, 8H), 7.56 (s, 4H), 7.23 (s, 2H), 7.04 (s, 1H), 5.65 (dt, J=5.9, 3.7 Hz, 1H), 5.45-5.35 (m, 1H), 4.04 (ddd, J=8.2, 5.4, 3.6 Hz, 1H), 3.34 (dd, J=11.2, 6.4 Hz, 1H), 3.19-3.08 (m, 3H), 3.06-2.89 (m, 2H), 2.56-2.44 (m, 2H), 2.41 (s, 3H), 2.33-1.84 (m, 9H), 1.84-1.43 (m, 15H), 1.35-1.24 (m, 12H), 1.23-1.14 (m, 5H), 1.09 (dd, J=10.0, 6.8 Hz, 6H), 0.95 (d, J=6.6 Hz, 3H), 0.60-0.46 (m, 1H). ³¹P-NMR (162 MHz, CD₂Cl₂) δ (ppm)=119.43. ¹⁹F-NMR (282 MHz, CD₂Cl₂) δ (ppm)=−62.86. HR-MS (ESI) m/z calcd for C₄H₆₆NOPIr [M]+ 848.4511 found 848.4512.

Va-22

The reaction was performed according to the above described procedure. The complex could be isolated as an orange solid (274 mg; 73% based on [Ir(COD)₂]BARF).

¹H-NMR (300 MHz, CD₂Cl₂): δ (ppm)=7.79-7.66 (m, 8H), 7.56 (s, 4H), 7.29 (s, 1H), 7.23 (s, 1H), 7.13 (s, 1H), 5.65 (td, J=5.9, 2.2 Hz, 1H), 5.46-5.40 (m, 1H), 4.42-4.36 (m, 1H), 3.38-3.30 (m, 1H), 3.19-2.86 (m, 3H), 2.65 (s, 3H), 2.59-2.44 (m, 2H), 2.42 (s, 3H), 2.38-1.54 (m, 20H), 1.46-0.98 (m, 21H), 0.70-0.58 (m, 1H). ³¹P-NMR (122 MHz, CD₂Cl₂) δ (ppm)=118.67. ¹⁹F-NMR (282 MHz, CD₂Cl₂) δ (ppm)=−62.86. HR-MS (ESI) m/z calcd for C₄₁H₆₀NOPIr [M]+ 806.4042 found 806.4053.

Va-23

The reaction was performed according to the above described procedure. The complex could be isolated as an orange solid (15.6 mg; 20% based on [Ir(COD)₂]BARF).

¹H-NMR (300 MHz, CD₂Cl₂) δ=8.43-8.36 (m, 2H), 7.92-7.85 (m, 1H), 7.81-7.69 (m, 12H), 7.68-7.53 (m, 4H), 5.73-5.65 (m, 1H), 5.50-5.43 (m, 1H), 4.58-4.43 (m, 2H), 3.25-3.12 (m, 1H), 3.08-2.94 (m, 1H), 2.92-2.77 (m, 1H), 2.72-1.45 (m, 40H). ¹⁹F-NMR (282 MHz, CDCl₃) δ=−62.42. ³¹P-NMR (122 MHz, CD₂Cl₂) δ=134.32. HR-MS (TOF) m/z calcd for C₄₂H₅₄NOPIr [M]+ 812.3572 found 812.3578.

EXAMPLES

Reactions were performed in metal autoclaves. Reaction mixtures were analyzed without workup via HPLC (Chiralpak IC column, 95/5 heptane/ethanol, 1 mL/min) or SFC (OZ-H column, 2.5% MeOH in supercritical CO₂, 3 mL/min) chromatography.

Example 1

A 600 mL autoclave was filled with 21 g of 1-(2,2,4-trimethyl-1-quinolyl)ethanone (97.5 mmol, 1 equiv), 0.74 g of catalyst (Va-1) (0.48 mmol, 0.5 mol %) and 450 mL of 2,2,2-trifluoroethanol. The autoclave was pressurized with argon three times, followed by pressurization with hydrogen twice. Subsequently, the autoclave was pressurized with 60 bar of hydrogen, heated to 85° C. and the reaction mixture was stirred at that temperature for 72 h. Chromatographic analysis of the cooled and de-pressurized reaction mixture showed complete conversion of starting material to the hydrogenated product 1-[2,2,4-trimethyl-3,4-dihydroquinolin-1-yl]ethanone (97% a/a purity according to SFC analysis) with an enantioselectivity of >98% ee.

Example 2

A 16 mL autoclave was filled with 0.7 g of 1-(2,2,4-trimethyl-1-quinolyl)ethanone (3.3 mmol, 1 equiv), 4.9 mg of catalyst (Va-1) (3.3 mol, 0.1 mol %) and 4.2 mL of 1,1,1,3,3,3-hexafluor-2-propanol. The autoclave was pressurized with argon three times, followed by pressurization with hydrogen twice. Subsequently, the autoclave was pressurized with 60 bar of hydrogen, heated to 85° C. and the reaction mixture was stirred at that temperature for 16 h. Chromatographic analysis of the cooled and de-pressurized reaction mixture showed 99.3% a/a HPLC conversion of starting material to the hydrogenated product 1-[2,2,4-trimethyl-3,4-dihydroquinolin-1-yl]ethanone with an enantioselectivity of 97.5% ee.

¹H-NMR (400 MHz, CDCl₃) δ (ppm)=7.12-7.21 (m, 3H), 6.90-6.97 (m, 1H), 2.7-2.83 (m, 1H), 2.09 (s, 3H), 1.83 (d, 1H), 1.72 (s, 3H), 1.49 (s, 3H), 1.35 (d, 2H), 1.22 (t, 1H). UPLC-MS: Re: 1.26 min, UV (210 nm): 100%, m/z (ES+) 218.3. GC-MS: R_(t): 4.78 min, m/z (RInt, %): 217 (15), 202 (10), 175 (5), 160 (100).

Example 3

A 16 mL autoclave was filled with 0.52 g of 1-(2,2,4-trimethyl-1-quinolyl)ethanone (2.41 mmol, 1 equiv), 9.2 mg of catalyst (Va-1) (6 mol, 0.25 mol %) and 6 mL of 1,1,1,3,3,3-hexafluoro-2-propanol. The autoclave was pressurized with argon three times, followed by pressurization with hydrogen twice. Subsequently, the autoclave was pressurized with 60 bar of hydrogen, heated to 85° C. and the reaction mixture was stirred at that temperature for 15 h. Chromatographic analysis of the cooled and de-pressurized reaction mixture showed 99.8% a/a HPLC conversion of starting material to the hydrogenated product 1-[2,2,4-trimethyl-3,4-dihydroquinolin-1-yl]ethanone with an enantioselectivity of 96.5% ee.

Example 4

A 100 mL autoclave was filled with 5 g of 1-(6-fluoro-2,2,4-trimethyl-1-quinolyl)ethanone (21.4 mmol, 1 equiv), 65 mg of catalyst (Va-1) (40 mol, 0.2 mol %) and 50 mL of 1,1,1,3,3,3-hexafluoro-2-propanol. The autoclave was pressurized with argon three times, followed by pressurization with hydrogen twice. Subsequently, the autoclave was pressurized with 60 bar of hydrogen, heated to 85° C. and the reaction mixture was stirred at that temperature for 36 h. From the cooled and de-pressurized reaction mixture the solvent was evaporated to dryness under reduced pressure giving 5.6 g of the hydrogenated product 1-(6-fluoro-2,2,4-trimethyl-3,4-dihydroquinolin-1-yl)ethanone (88.9% w/w purity, 98.7% yield) with an enantioselectivity of 98% ee.

Example 5

A 16 mL autoclave was filled with 0.25 g of 1-(2,2-dimethyl-4-propyl-1-quinolyl)ethanone (88.7% a/a HPLC, 1.02 mmol, 1 equiv), 7.8 mg of catalyst (Va-1) (5 μmol, 0.5 mol %) and 5 mL of 1,1,1,3,3,3-hexafluoro-2-propanol. The autoclave was pressurized with argon three times, followed by pressurization with hydrogen twice. Subsequently, the autoclave was pressurized with 60 bar of hydrogen, heated to 85° C. and the reaction mixture was stirred at that temperature for 15 h. Chromatographic analysis of the cooled and de-pressurized reaction mixture showed 92.4% a/a HPLC conversion of starting material to the hydrogenated product 1-(2,2-dimethyl-4-propyl-3,4-dihydroquinolin-1-yl)ethanone with an enantioselectivity of 81.2% ee.

Example 6: Comparison Using Reaction Conditions from Example 6 of DE112015001290 T5

A 25 mL autoclave was filled with 0.5 g of 1-(2,2,4-trimethyl-1-quinolyl)ethanone (2.3 mmol, 1 equiv), 43.9 mg of catalyst (Va-1) (29 mol, 1.2 mol %) and 12.2 mL of 2,2,2-trifluoroethanol. The autoclave was pressurized with argon three times, followed by pressurization with hydrogen twice. Subsequently, the autoclave was pressurized with 70 bar of hydrogen, heated to 90° C. and the reaction mixture was stirred at that temperature for 9 h. Chromatographic analysis of the cooled and de-pressurized reaction mixture showed 70% a/a HPLC conversion of starting material to the hydrogenated product 1-[2,2,4-trimethyl-3,4-dihydroquinolin-1-yl]ethanone with an enantioselectivity of 95.5% ee.

Example 7: Comparison Using Catalyst from Example 6 of DE112015001290 T5

In the comparative example 7 the following commercially available Cy-UbaPHOX (CAS 583844-38-6) catalyst was used:

A 16 mL autoclave was filled with 0.7 g of 1-(2,2,4-trimethyl-1-quinolyl)ethanone (3.3 mmol, 1 equiv), 5.6 mg of catalyst (Cy-UbaPHOX, CAS 880262-14-6) (3.3 mol, 0.1 mol %) and 4.2 mL of 1,1,1,3,3,3-hexafluor-2-propanol. The autoclave was pressurized with argon three times, followed by pressurization with hydrogen twice. Subsequently, the autoclave was pressurized with 60 bar of hydrogen, heated to 85° C. and the reaction mixture was stirred at that temperature for 16 h. Chromatographic analysis of the cooled and de-pressurized reaction mixture showed 84% a/a HPLC conversion of starting material to the hydrogenated product 1-[2,2,4-trimethyl-3,4-dihydroquinolin-1-yl]ethanone with an enantioselectivity of 81.7% ee.

Conclusion from Comparative Examples 6 and 7

Both the catalyst VI-a used in this invention (e.g. example 2) and the reaction conditions are superior to the benchmark catalyst and conditions from DE112015001290 T5 (example 6). For optimal results, the reaction conditions and the catalysts (e.g. Va-1) of this invention have to be used in combination (e.g. example 2). Other catalysts from this invention like Va-4, Va-6, Va-8, Va-10 and Va-22 show even superior activity to both Va-1 and Cy-UbaPHOX.

Detailed Comparison of Experiments with DE112015001290 T5:

Catalyst Conv. ee Example Catalyst [mol %] Solvent [%] [%] DE112015001290 T5, Ir 1.2 Trifluoro- 14.3 31.3 example 6 catalyst (I) ethanol Present invention, Va-1 1.2 Trifluoro- 70 95.5 example 6 ethanol

The comparison shows that catalyst Va-1 of this invention is superior conversion and enantiomeric excess (ee) to Ir catalyst (I) from DE112015001290 T5 (example 6) under the conditions used in DE112015001290 T5, example 6 (1.2 mol % of catalyst in trifluoroethanol).

Catalyst Conv. ee Example Catalyst [mol %] Solvent [%] [%] Present invention, Ir 0.1 Hexafluoroiso- 84 81.7 example 7 catalyst (I) propanol Present invention, Va-1 0.1 Hexafluoroiso- 100 97.5 example 2 propanol

The comparison shows that catalyst Va-1 of this invention is superior in conversion and enantiomeric excess (ee) to Ir catalyst (I) from DE112015001290 T5, example 6 under the conditions used in the present patent application (0.1 mol % of catalyst in hexafluoroisopropanol).

Additionally, the conditions used in the present patent application (0.1 mol % of catalyst in hexafluoroisopropanol) are superior in conversion, enantiomeric excess (ee) and catalyst amount to the conditions used in DE112015001290 T5, example 6 (1.2 mol % of catalyst in trifluoroethanol).

Examples 8-11

Under an inert gas atmosphere, one well of a 96 well-plate autoclave was filled with 9.8 mg of 1-(2,2,4-trimethyl-1-quinolyl)ethanone (45.5 mol, 1 equiv) and 1.82 mol of catalyst (4 mol %, see table 1) in 0.49 mL of 2,2,2-trifluoroethanol. The autoclave was pressurized with 30 bar of hydrogen, heated to 40° C. and the reaction mixture was shaken at that temperature for 16 h. Chromatographic analysis of the cooled and de-pressurized reaction mixture showed the % a/a HPLC conversion rates of starting material to the hydrogenated product 1-[2,2,4-trimethyl-3,4-dihydroquinolin-1-yl]ethanone. The % a/a HPLC conversion rates and enantioselectivities are depicted in table 1 below.

Conversion Ex. Catalyst¹⁾ Ligand L* Anion Y (% a/a HPLC) % ee 8 [IrL*(COD)]Y

BARF²⁾ 47 89 9 [IrL*(COD)]Y

BARF²⁾ 47 93 10 [IrL*(COD)]Y

BARF²⁾ 55 91 11 [IrL*(COD)]Y

BARF²⁾ 44 51 ¹⁾The catalyst used in example 8 was prepared according to the method disclosed in S. Kaiser et al., Angew. Chem. Int. Ed. 2006, 45, 5194-5197; the catalysts used in examples 9 and 10 were prepared according to the method disclosed in W. J. Drury III et al., Angew. Chem. Int. Ed. 2004, 43, 70-74; the catalyst used in example 11 was formed in situ from [Ir(COD)₂]BARF and the depicted ligand. ²⁾BARF = Tetrakis[3,5-bis(trifluoromethyl)phenyl]borate

Examples 12-39

The Ir-complex (catalyst loading given) and 0.64 g 1-(2,2,4-trimethyl-1-quinolyl)ethanone (3 mmol) were placed in an 8-mL autoclave vial containing a PTFE-coated stirring bar. The autoclave vial was closed using a screw cap with septum and flushed with argon (10 min). Hexafluoroisopropanol (HFIP, 4 mL) was added via the septum to the vial. The vial was placed in an argon containing autoclave and the autoclave was flushed with argon (10 min). The autoclave was pressurized with hydrogen gas (10 bar) and subsequently depressurized to atmospheric pressure three times. After this the autoclave was pressurized to 60 bar hydrogen pressure and was placed in a suitable alumina block. After heating to 85° C. the reaction was kept at this temperature for the given time. After cooling to room temperature and depressurizing, the vial was taken out of the autoclave and the reactions outcome was determined by GC-FID analysis (diluted with EtOH) and the enantiomeric excess by HPLC analysis.

Reaction catalyst Conversion Enantiomeric time loading GC excess Example Catalyst (h) (mol %) (% a/a) (% ee) 12 Va-1 16 0.1 99.2 98.0 13 Va-1 6 0.1 81.5 97.5 14 Va-2 6 0.1 94.5 97.5 15 Vb-3 6 0.05 88.2 97.6 16 Va-4 16.5 0.05 94.4 97.3 17 Va-4 16 0.1 99.4 96.0 18 Va-4 16.5 0.1 92.0 97.0 19 Vb-5 16 0.05 98.4 96.8 20 Vb-5 6 0.025 67.2 97.3 21 Va-6 6 0.025 91.6 97.3 22 Vb-7 16.5 0.05 98.9 95.8 23 Vb-7 16.5 0.025 79.5 97.5 24 Va-8 16 0.025 94.1 97.5 25 Va-9 16.5 0.025 81.7 97.9 26 Va-10 16.5 0.025 98.0 98.1 27 Va-11 16.5 0.025 42.2 94.5 28 Va-12 16 0.05 92.4 96.9 29 Va-13 16.5 0.1 91.2 97.0 30 Va-14 16 0.05 64.7 92.4 31 Va-15 16 0.05 34.6 83.2 32 Va-16 16 0.05 87.9 95.8 33 Vb-17 16 0.1 30 90.0 34 Va-18 16 0.1 76.0 96.0 35 Va-19 16 0.025 7.2 70.8 36 Va-20 16 0.025 60 92.1 37 Va-21 16 0.025 74 98.0 38 Va-22 1 0.025 97.5 97.3 39 Va-23 16 0.1 30 94 

1: A process for preparing a compound of the formula (Ia) or (b),

wherein R¹ is C₁-C₆-alkyl, C₁-C₆-haloalkyl, C₁-C₆-alkoxy-C₁-C₆-alkyl, C₃-C₆-cycloalkyl, C₆-C₁₄-aryl, or C₆-C₁₄-aryl-C₁-C₄-alkyl, wherein the C₁-C₆-alkyl, C₃-C₆-cycloalkyl and the C₁-C₆-alkoxy in the C₁-C₆-alkoxy-C₁-C₆-alkyl moiety, are optionally substituted by 1 to 3 substituents independently selected from the group consisting of halogen, C₁-C₄-alkoxy, C₁-C₄-haloalkyl, C₁-C₄-haloalkoxy and phenyl, wherein the phenyl may be substituted by one to five substituents selected independently from each other from halogen, C₁-C₄-alkyl, C₁-C₄-alkoxy, C₁-C₄-haloalkyl, and C₁-C₄-haloalkoxy, and wherein the C₆-C₁₄-aryl and the C₆-C₁₄-aryl in the C₆-C₁₄-aryl-C₁-C₄-alkyl moiety in each case is unsubstituted or substituted by one to five substituents selected from the group consisting of halogen, C₁-C₄-alkyl, C₁-C₄-haloalkyl, C₁-C₄-alkoxy and C₁-C₄-haloalkoxy, R² and R³ are the same and are selected from the group consisting of hydrogen, C₁-C₆-alkyl, C₁-C₆-haloalkyl and C₁-C₆-alkoxy-C₁-C₆-alkyl, or R² and R³ together with the carbon to which they are bonded, form a C₃-C₆-cycloalkyl ring, R⁴ is hydrogen, C₁-C₆-alkyl, C₁-C₆-haloalkyl, C₁-C₆-alkoxy, C₁-C₆-haloalkoxy, C₁-C₆-alkylamino, C₂-C₆-alkenyl, C₂-C₆-alkynyl, C₃-C₆-cycloalkyl, C₃-C₆-cycloalkyl-C₁-C₄-alkyl, C₂-C₆-alkenyloxy, 9-flurorenylmethyleneoxy, C₆-C₁₄-aryl, C₆-C₁₄-aryloxy, C₆-C₁₄-aryl-C₁-C₄-alkyloxy or C₆-C₄-aryl-C₁-C₄-alkyl, wherein the C₆-C₁₄-aryl as such or as part of a composite substituent is unsubstituted or substituted by one to five substituents selected from the group consisting of halogen, C₁-C₄-alkyl, C₁-C₄-haloalkyl, C₁-C₄-alkoxy and C₁-C₄-haloalkoxy, n is 0, 1, 2, 3 or 4, each substituent R⁵, if present, is independently selected from the group consisting of halogen, C₁-C₆-alkyl, C₁-C₆-haloalkyl, C₁-C₆-alkoxy, hydroxyl, amino and —C(═O)—C₁-C₆-alkyl, comprising enantioselective hydrogenation of a compound of the formula (II)

wherein the substituents R¹, R², R³, R⁴, R⁵ and the integer n are each as defined for the compound of the formula (a) or (b), in presence of a chiral iridium catalyst, characterized in that the chiral iridium catalyst comprises a chiral ligand of the formula (IIIa), (IIIb), (IVa) or (IVb),

wherein R⁶, R⁷ and R⁸ are independently from one another selected from hydrogen, halogen, C₁-C₆-alkyl, C₁-C₆-haloalkyl, C₁-C₆-alkoxy, C₂-C₆-alkenyl, C₂-C₆-alkynyl, C₃-C₇-cycloalkyl, C₃-C₇-cycloalkyl-C₁-C₄-alkyl, C₆-C₁₄-aryl and C₆-C₁₄-aryl-C₁-C₄-alkyl, wherein the C₁-C₆-alkyl, C₂-C₆-alkenyl, C₂-C₆-alkynyl, C₃-C₇-cycloalkyl and the C₃-C₇-cycloalkyl in the C₃-C₇-cycloalkyl-C₁-C₄-alkyl moiety are optionally substituted by 1 to 3 substituents independently selected from the group consisting of halogen, C₁-C₄-alkyl, C₁-C₄-alkoxy and C₁-C₄-haloalkyl and C₁-C₄-haloalkoxy, and wherein the C₆-C₁₄-aryl and the C₆-C₁₄-aryl in the C₆-C₁₄-aryl-C₁-C₄-alkyl moiety are optionally substituted by one to five substituents selected from the group consisting of halogen, C₁-C₄-alkyl, C₁-C₄-haloalkyl, C₁-C₄-alkoxy, C₁-C₄-haloalkoxy and phenyl, wherein the phenyl again is unsubstituted or substituted by one to five C₁-C₆-alkyl substituents, R⁹ and R¹⁰ are independently from one another selected from the group consisting of C₁-C₆-alkyl, C₂-C₆-alkenyl, C₂-C₆-alkynyl, C₁-C₆-alkoxy, di(C₁-C₆-alkyl)amino, C₃-C₁₂-cycloalkyl, C₃-C₁₂-cycloalkyl-C₁-C₄-alkyl, C₆-C₁₄-aryl, C₆-C₁₄-aryloxy and C₆-C₁₄-aryl-C₁-C₄-alkyl, wherein the C₁-C₆-alkyl, C₂-C₆-alkenyl, C₂-C₆-alkynyl, C₁-C₆-alkoxy and di(C₁-C₆-alkyl)amino are optionally substituted by 1 to 3 substituents independently selected from the group consisting of halogen, C₁-C₄-alkoxy, C₁-C₄-haloalkyl, C₁-C₄-haloalkoxy and phenyl, wherein the phenyl may be substituted by one to five substituents selected independently from each other from halogen, C₁-C₄-alkyl, C₁-C₄-alkoxy, C₁-C₄-haloalkyl, and C₁-C₄-haloalkoxy, and wherein the C₆-C₁₄-aryl, C₆-C₁₄-aryloxy and C₃-C₁₂-cycloalkyl, in each case as such or as part of a composite substituent, are optionally substituted by one to five substituents selected from the group consisting of halogen, C₁-C₄-alkyl, C₁-C₄-haloalkyl, C₁-C₄-alkoxy, C₁-C₄-haloalkoxy and phenyl, wherein the phenyl is unsubstituted or substituted by one to five C₁-C₆-alkyl substituents or R⁹ and R¹⁰ together with the phosphorus atom to which they are bonded, form a phospholane ring, which may be substituted with one or two C₁-C₆-alkyl groups, or R⁹ and R¹⁰ together form

where the bonds identified by “x” and “y” are both bonded directly to the phosphorus atom, p and q are independently from one another selected from 0, 1 and 2, R¹¹ and R¹² are independently selected from C₁-C₆-alkyl and phenyl, which may be substituted by one to five substituents selected from the group consisting of halogen, C₁-C₄-alkyl, C₁-C₄-alkoxy and phenyl, which may be substituted by one or two C₁-C₄-alkyl substituents, m is 1 or 2, A is

where the bond identified by “*” is bonded directly to the phosphorus atom and where the bond identified by “#” is bonded directly to the oxazoline moiety, R¹³ is C₁-C₆-alkyl, C₁-C₆-haloalkyl, C₃-C₂-cycloalkyl, C₃-C₂-cycloalkyl-C₁-C₄-alkyl, C₁-C₄-alkyl-C₃-C₇-cycloalkyl, C₆-C₁₄-aryl or C₆-C₁₄-aryl-C₁-C₄-alkyl, wherein the C₆-C₁₄-aryl and the C₆-C₁₄-aryl in the C₆-C₁₄-aryl-C₁-C₄-alkyl moiety in each case is unsubstituted or substituted by one to five substituents selected from the group consisting of halogen, C₁-C₄-alkyl, C₁-C₄-haloalkyl, C₁-C₄-alkoxy and C₁-C₄-haloalkoxy, R¹⁴ and R¹⁵ are independently from one another selected from the group consisting of hydrogen, C₁-C₆-alkyl, C₁-C₆-haloalkyl, C₃-C₁₂-cycloalkyl, C₃-C₇-cycloalkyl-C₁-C₄-alkyl, C₁-C₄-alkyl-C₃-C₇-cycloalkyl, C₆-C₁₄-aryl and C₆-C₁₄-aryl-C₁-C₄-alkyl, wherein the C₆-C₁₄-aryl and the C₆-C₁₄-aryl in the C₆-C₁₄-aryl-C₁-C₄-alkyl moiety in each case is unsubstituted or substituted by one to five substituents selected from the group consisting of halogen, C₁-C₄-alkyl, C₁-C₄-haloalkyl, C₁-C₄-alkoxy and C₁-C₄-haloalkoxy, or R¹⁴ and R¹⁵ together with the carbon to which they are bonded, form a C₅-C₆-cycloalkyl ring, R¹⁶ and R¹⁷ are independently from one another selected from the group consisting of C₁-C₆-alkyl, C₂-C₆-alkenyl, C₂-C₆-alkynyl, C₁-C₆-alkoxy, di(C₁-C₆-alkyl)amino, C₃-C₁₂-cycloalkyl, C₃-C₁₂-cycloalkyl-C₁-C₄-alkyl, C₆-C₁₄-aryl, C₆-C₁₄-aryloxy and C₆-C₁₄-aryl-C₁-C₄-alkyl, wherein the C₁-C₆-alkyl, C₂-C₆-alkenyl, C₂-C₆-alkynyl, C₁-C₆-alkoxy, C₁-C₆-cycloalkyl and di(C₁-C₆-alkyl)amino are optionally substituted by 1 to 3 substituents independently selected from the group consisting of halogen, C₁-C₄-alkoxy, C₁-C₄-haloalkyl, C₁-C₄-haloalkoxy and phenyl, wherein the phenyl may be substituted by one to five substituents selected independently from each other from halogen, C₁-C₄-alkyl, phenyl, C₁-C₄-alkoxy, C₁-C₄-haloalkyl, and C₁-C₄-haloalkoxy, and wherein the C₆-C₁₄-aryl, the C₆-C₁₄-aryl in the C₆-C₁₄-aryl-C₁-C₄-alkyl, the C₆-C₁₄-aryloxy and C₃-C₁₂-cycloalkyl, in each case as such or as part of a composite substituent, are optionally substituted by one to five substituents selected from the group consisting of halogen, C₁-C₄-alkyl, phenyl, C₁-C₄-haloalkyl, C₁-C₄-alkoxy and C₁-C₄-haloalkoxy, or R¹⁶ and R¹⁷ together with the phosphorus atom to which they are bonded, form a phospholane ring, which may be substituted with one or two C₁-C₆-alkyl groups or R¹⁶ and R¹⁷ together form G¹ or G², wherein G¹ and G² are as defined for the substituents R⁹ and R¹⁰ of the ligands of the formulae (IIIa) and (IIIb). 2: The process according to claim 1, wherein R¹ is C₁-C₆-alkyl or C₆-C₁₄-aryl-C₁-C₄-alkyl, wherein C₆-C₁₄-aryl in the C₆-C₁₄-aryl-C₁-C₄-alkyl moiety is unsubstituted or substituted by one to five substituents selected from the group consisting of halogen, C₁-C₄-alkyl, C₁-C₄-haloalkyl, C₁-C₄-alkoxy and C₁-C₄-haloalkoxy R² and R³ are the same and are selected from C₁-C₄-alkyl, R⁴ is C₁-C₄-alkyl, C₁-C₄-haloalkyl, C₁-C₄-alkoxy, C₁-C₄-haloalkoxy, phenyl or benzyl, n is 0, 1 or 2, and each substituent R⁵, if present, is independently selected from the group consisting of halogen, C₁-C₆-alkyl and C₁-C₆-haloalkyl. 3: The process according to claim 1, wherein R¹ is methyl, ethyl or n-propyl, R² and R³ are methyl, R⁴ is C₁-C₄-alkyl, n is 0, 1 or 2, and each substituent R⁵, if present, is independently selected from the group consisting of halogen and C₁-C₆-alkyl. 4: The process according to claim 1, wherein the chiral iridium catalyst comprises a chiral ligand of the formula (IIa) or (IIIb), wherein R⁶ is C₁-C₆-alkyl, C₁-C₆-haloalkyl, C₃-C₇-cycloalkyl or C₆-C₁₄-aryl, wherein the C₆-C₁₄-aryl is unsubstituted or substituted by one to five substituents selected from the group consisting of halogen, C₁-C₄-alkyl, C₁-C₄-haloalkyl, C₁-C₄-alkoxy, C₁-C₄-haloalkoxy and phenyl, wherein the phenyl again is unsubstituted or substituted by one to five C₁-C₆-alkyl substituents, R⁷ and R⁸ are independently from one another selected from the group consisting of hydrogen, C₁-C₆-alkyl, C₁-C₆-alkoxy, C₆-C₁₄-aryl or C₁-C₆-haloalkyl, wherein the C₆-C₁₄-aryl is unsubstituted or substituted by one to five C₁-C₄-alkyl substituents, R⁹ and R¹⁰ are independently from one another selected from the group consisting of C₁-C₆-alkyl, C₁-C₆-alkoxy, di(C₁-C₆-alkyl)amino, C₃-C₁₂-cycloalkyl, C₆-C₁₄-aryl, C₆-C₁₄-aryloxy and C₆-C₁₄-aryl-C₁-C₄-alkyl, wherein the C₁-C₆-alkyl, C₁-C₆-alkoxy and di(C₁-C₆-alkyl)amino moieties are optionally substituted by 1 to 3 substituents independently selected from the group consisting of halogen, C₁-C₄-alkoxy, C₁-C₄-haloalkyl, C₁-C₄-haloalkoxy and phenyl, wherein the phenyl may be substituted by one to five substituents selected independently from each other from halogen, C₁-C₄-alkyl, C₁-C₄-alkoxy, C₁-C₄-haloalkyl, and C₁-C₄-haloalkoxy, and wherein the C₆-C₁₄-aryloxy, C₃-C₁₂-cycloalkyl and C₆-C₁₄-aryl, as such or as part of a composite substituent, in each case is unsubstituted or substituted by one to five substituents selected from the group consisting of halogen, C₁-C₄-alkyl, C₁-C₄-haloalkyl, C₁-C₄-alkoxy, C₁-C₄-haloalkoxy and phenyl, wherein the phenyl is unsubstituted or substituted by one to five C₁-C₆-alkyl substituents, or R⁹ and R¹⁰ together with the phosphorus atom to which they are bonded, form a phospholane ring, which may be substituted with one or two C₁-C₆-alkyl groups, m is 1 or 2, or the chiral iridium catalyst comprises a chiral ligand of the formula (IVa) or (IVb), wherein A is

where the bond identified by “*” is bonded directly to the phosphorus atom and where the bond identified by “#” is bonded directly to the oxazoline moiety, R¹³ is C₃-C₆-alkyl, C₃-C₁₂-cycloalkyl, C₆-C₁₄-aryl or C₆-C₁₄-aryl-C₁-C₄-alkyl, wherein the C₆-C₁₄-aryl and the C₆-C₁₄-aryl in the C₆-C₁₄-aryl-C₁-C₄-alkyl moiety in each case is unsubstituted or substituted by one to five substituents selected from the group consisting of halogen, C₁-C₄-alkyl, C₁-C₄-haloalkyl, C₁-C₄-alkoxy and C₁-C₄-haloalkoxy, R¹⁴ and R¹⁵ are independently from one another selected from the group consisting of C₁-C₆-alkyl, C₆-C₁₄-aryl, C₃-C₁₂-cycloalkyl, and C₆-C₁₄-aryl-C₁-C₄-alkyl, wherein the C₆-C₁₄-aryl and the C₆-C₁₄-aryl in the C₆-C₁₄-aryl-C₁-C₄-alkyl moiety is unsubstituted or substituted by one to five substituents selected from the group consisting of halogen, C₁-C₄-alkyl, C₁-C₄-haloalkyl, C₁-C₄-alkoxy and C₁-C₄-haloalkoxy, or R¹⁴ and R¹⁵ together with the carbon to which they are bonded, form a C₅-C₆-cycloalkyl ring, and R¹⁶ and R¹⁷ are independently from one another selected from the group consisting of C₁-C₆-alkyl, C₃-C₁₂-cycloalkyl, C₆-C₁₄-aryl and C₆-C₁₄-aryl-C₁-C₄-alkyl, wherein the C₁-C₆-alkyl is optionally substituted by 1 to 3 substituents independently selected from the group consisting of halogen, C₁-C₄-alkoxy, C₁-C₄-haloalkyl, C₁-C₄-haloalkoxy and phenyl, wherein the phenyl may be substituted by one to five substituents selected independently from each other from halogen, C₁-C₄-alkyl, C₁-C₄-alkoxy, C₁-C₄-haloalkyl, and C₁-C₄-haloalkoxy, and wherein the C₆-C₁₄-aryl and the C₆-C₁₄-aryl in the C₆-C₁₄-aryl-C₁-C₄-alkyl moiety in each case is unsubstituted or substituted by one to five substituents selected from the group consisting of halogen, C₁-C₄-alkyl, phenyl, C₁-C₄-haloalkyl, C₁-C₄-alkoxy and C₁-C₄-haloalkoxy, or R¹⁶ and R¹⁷ together with the phosphorus atom to which they are bonded, form a phospholane ring, which may be substituted with one or two C₁-C₆-alkyl groups. 5: The process according to claim 1, wherein the chiral iridium catalyst comprises a chiral ligand of the formula (IIa) or (IIIb), wherein R⁶ is selected from the group consisting of 1-naphtyl, 2-naphtyl, 9-antracenyl, 9-phenantryl or phenyl, which is unsubstituted or substituted by one to five substituents selected from the group consisting of halogen, C₁-C₄-alkoxy, C₁-C₄-alkyl, C₁-C₄-haloalkyl and phenyl, wherein the phenyl again is unsubstituted or substituted by one to five C₁-C₆-alkyl substituents, R⁷ and R⁸ are independently from one another hydrogen or C₁-C₆-alkyl, R⁹ and R¹⁰ are independently from one another selected from the group consisting of ethyl, iso-propyl, sec-butyl, iso-butyl, tert-butyl, cyclohexyl, cyclopentyl, adamantyl and benzyl, and m is 1 or 2, or the chiral iridium catalyst comprises a chiral ligand of the formula (IVa) or (IVb), wherein A is

where the bond identified by “*” is bonded directly to the phosphorus atom and where the bond identified by “#” is bonded directly to the oxazoline moiety, R¹³ is selected from the group consisting of C₃-C₆-alkyl, C₃-C₂-cycloalkyl, C₆-C₁₄-aryl or C₆-C₁₄-aryl-C₁-C₄-alkyl, wherein the C₆-C₁₄-aryl and the C₆-C₁₄-aryl in the C₆-C₁₄-aryl-C₁-C₄-alkyl moiety in each case is unsubstituted or substituted by one to five substituents selected from the group consisting of halogen or C₁-C₄-alkyl, R¹⁴ and R¹⁵ are independently from one another selected from the group consisting of C₁-C₆-alkyl, and C₆-C₁₄-aryl-C₁-C₄-alkyl, wherein the C₆-C₁₄-aryl in the C₆-C₁₄-aryl-C₁-C₄-alkyl moiety is unsubstituted or substituted by one to five substituents selected from the group consisting of halogen and C₁-C₄-alkyl, and R¹⁶ and R¹⁷ are independently from one another selected from the group consisting of C₁-C₆-alkyl, C₃-C₁₂-cycloalkyl, C₆-C₁₄-aryl and C₆-C₁₄-aryl-C₁-C₄-alkyl, wherein the C₆-C₁₄-aryl and the C₆-C₁₄-aryl in the C₆-C₁₄-aryl-C₁-C₄-alkyl moiety in each case is unsubstituted or substituted by one to five substituents selected from the group consisting of halogen, C₁-C₄-alkyl, phenyl, C₁-C₄-haloalkyl, C₁-C₄-alkoxy and C₁-C₄-haloalkoxy, or R¹⁶ and R¹⁷ together with the phosphorus atom to which they are bonded, form a phospholane ring, which may be substituted with one or two C₁-C₆-alkyl groups. 6: The process according to claim 1, wherein the hydrogenation is conducted using hydrogen gas at a pressure of from 1 to 300 bar. 7: The process according to claim 1, wherein the amount of iridium catalyst used is within the range of from 0.001 mol % to 5 mol %, based on the amount of the compound of the formula (II). 8: The process according to claim 1, wherein the hydrogenation is conducted at a temperature within the range of from 20° C. to 130° C. 9: The process according to claim 1, wherein the hydrogenation is conducted in presence of a solvent selected from the group consisting of 2,2,2,-trifluoroethanol, 1,1,1,3,3,3-hexafluoro-2-propanol, 1,2-dichloroethane, tetrafluoropropanol, and mixtures thereof. 10: The process according to claim 1, wherein the chiral iridium catalyst has the general formula (Va), (Vb), (VIa) or (VIb):

wherein R⁶ is selected from the group consisting of 1-naphtyl, 2-naphtyl, 9-antracenyl, 9-phenantryl or phenyl, wherein 1-naphtyl, 2-naphtyl, 9-antracenyl, 9-phenantryl and phenyl are unsubstituted or substituted by one to five substituents selected from the group consisting of halogen, C₁-C₄-alkoxy, C₁-C₄-alkyl, C₁-C₄-haloalkyl and phenyl, wherein the phenyl again is unsubstituted or substituted by one to five C₁-C₆-alkyl substituents, R⁷ and R⁸ are independently from one another hydrogen or C₁-C₆-alkyl, R⁹ and R¹⁰ are independently from one another selected from the group consisting of ethyl, iso-propyl, sec-butyl, iso-butyl, tert-butyl, cyclohexyl, cyclopentyl, adamantyl and benzyl, m is 1 or 2, R¹³ is iso-propyl, sec-butyl, iso-butyl, tert-butyl, phenyl or benzyl, R¹⁴ and R¹⁵ are independently from one another selected from the group consisting of C₁-C₆-alkyl, and C₆-C₁₄-aryl-C₁-C₄-alkyl, wherein the C₆-C₁₄-aryl in the C₆-C₁₄-aryl-C₁-C₄-alkyl moiety is unsubstituted or substituted by one to five substituents selected from the group consisting of halogen and C₁-C₄-alkyl, R¹⁶ and R¹⁷ are independently from one another phenyl, 1-naphthyl or 2-naphthyl, which in each case is unsubstituted or substituted by one to five substituents selected from the group consisting of halogen, C₁-C₄-alkyl and C₁-C₄-haloalkyl, and R¹⁸ is phenyl, which is unsubstituted or substituted with one to five substituents selected from fluorine and C₁-C₄-haloalkyl. 11: The process according to claim 10, wherein R⁶ is selected from the group consisting of phenyl, 2,6- or 3,5-dimethylphenyl, 2,4,6-trimethylphenyl, 4-tert-butylphenyl, 4-methoxyphenyl, 3,5-bis-tert-butyl-4-methoxyphenyl, 4-tert-butyl-2,6-dimethylphenyl, 4-fluorophenyl, 4-trifluoromethylphenyl, 1-naphtyl, 9-antracenyl 2,4,6-triisopropylphenyl, 9-phenantryl or 2,6-diethyl-4-methylphenyl, R⁷ is hydrogen, R⁸ is hydrogen or methyl, R⁹ and R¹⁰ are each the same and tert-butyl, adamantly, cyclopentyl or cyclohexyl, m is 1 or 2, R¹³ is tert-butyl, R¹⁴ and R¹⁵ are methyl, R¹⁶ and R¹⁷ are independently from one another phenyl, which is substituted by one or two methyl, in particular R¹⁶ and R¹⁷ are each the same and 2-methylphenyl or 3,5-dimethylphenyl, and R¹⁸ is 3,5-bis(trifluoromethyl)phenyl. 12: The process according to claim 1, wherein the chiral iridium catalyst comprises a chiral ligand of the formula (IIIa) or (IIIb), wherein R⁶ is selected from the group consisting of 1-naphtyl, 2-naphtyl, 9-antracenyl, 9-phenantryl or phenyl, which is unsubstituted or substituted by one to five substituents selected from the group consisting of halogen, C₁-C₄-alkoxy, C₁-C₄-alkyl, C₁-C₄-haloalkyl and phenyl, wherein the phenyl again is unsubstituted or substituted by one to five C₁-C₆-alkyl substituents, R⁷ and R⁸ are independently from one another hydrogen or C₁-C₆-alkyl, R⁹ and R¹⁰ are independently from one another selected from the group consisting of ethyl, iso-propyl, sec-butyl, iso-butyl, tert-butyl, cyclohexyl, cyclopentyl, adamantyl and benzyl, and m is 1 or
 2. 13: The process according to claim 12, wherein R⁶ is selected from the group consisting of phenyl, 2,6- or 3,5-dimethylphenyl, 2,4,6-trimethylphenyl, 4-tert-butylphenyl, 4-methoxyphenyl, 3,5-bis-tert-butyl-4-methoxyphenyl, 4-tert-butyl-2,6-dimethylphenyl, 4-fluorophenyl, 4-trifluoromethylphenyl, 1-naphtyl, 9-antracenyl 2,4,6-triisopropylphenyl, 9-phenantryl or 2,6-diethyl-4-methylphenyl, R⁷ is hydrogen R⁸ is hydrogen or methyl, R⁹ and R¹⁰ are each the same and tert-butyl, cyclopentyl or cyclohexyl, and m is
 1. 14: The process according to claim 1, wherein the chiral iridium catalyst comprises a chiral ligand of the formula (IVa) or (IVb), wherein A is

where the bond identified by “*” is bonded directly to the phosphorus atom and where the bond identified by “#” is bonded directly to the oxazoline moiety, R¹³ is iso-propyl, sec-butyl, iso-butyl, tert-butyl, phenyl or benzyl, R¹⁴ and R¹⁵ are independently from one another selected from the group consisting of C₁-C₆-alkyl, and C₆-C₁₄-aryl-C₁-C₄-alkyl, wherein the C₆-C₁₄-aryl in the C₆-C₁₄-aryl-C₁-C₄-alkyl moiety is unsubstituted or substituted by one to five substituents selected from the group consisting of halogen and C₁-C₄-alkyl, R¹⁶ and R¹⁷ are independently from one another phenyl, 1-naphthyl or 2-naphthyl, which in each case is unsubstituted or substituted by one to five C₁-C₄-alkyl substituents. 15: The process according to claim 14, wherein R¹³ is tert-butyl, R¹⁴ and R¹⁵ are methyl, and R¹⁶ and R¹⁷ are independently from one another phenyl, which is substituted by one or two methyl groups. 16: The process according to claim 1, wherein the chiral iridium catalyst comprises a chiral ligand of the formula (IIIa) or (IIIb), wherein R⁶ is selected from the group consisting of phenyl, 2,6- or 3,5-dimethylphenyl, 2,4,6-trimethylphenyl, 4-tert-butylphenyl, 4-methoxyphenyl, 3,5-bis-tert-butyl-4-methoxyphenyl, 4-tert-butyl-2,6-dimethylphenyl, 4-fluorophenyl, 4-trifluoromethylphenyl, 1-naphtyl, 9-antracenyl, 2,4,6-triisopropylphenyl, 9-phenantryl and 2,6-diethyl-4-methylphenyl, R⁷ is hydrogen, R⁸ is C₁-C₆-alkoxy, R⁹ and R¹⁰ are independently from one another selected from the group consisting of ethyl, iso-propyl, sec-butyl, iso-butyl, tert-butyl, cyclohexyl, cyclopentyl, adamantyl and benzyl, and m is
 1. 